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Sample records for unit heaters variation

  1. Lightweight Radioisotope Heater Unit (LWRHU) production for the Cassini mission

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, G.H.

    1996-06-01

    The Lightweight Radioisotope Heater Unit (LWRHU) is a {sup 238}PuO{sub 2} fueled heat source designed to provide a thermal watt of power for space missions. The LWRHU will be used to maintain the temperature of various components on the spacecraft at the required level. The heat source consists of a {sup 238}PuO{sub 2} fuel pellet, a Pt-30Rh capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos has fabricated 180 heater units, which will be used on the Cassini mission. This report summarizes the specifications, fabrication processes, and production data for the heat sources fabricated at Los Alamos.

  2. Fabrication of light weight radioisotope heater unit hardware components

    Science.gov (United States)

    McNeil, Dennis C.

    1996-03-01

    The Light Weight Radioisotope Heater Unit (LWRHU) is planned to be used on the National Aeronautics and Space Administration (NASA) Cassini Mission, to provide localized thermal energy as strategic locations on the spacecraft. These one watt heater units will support the operation of many on-board instruments that require a specific temperature range to function properly. The system incorporates a fuel pellet encapsulated in a vented metallic clad fabricated from platinum-30% rhodium (Pt-30%Rh) tubing, sheet and foil materials. To complete the package, the clad assemblies are placed inside a combination of graphite components. This report describes the techniques employed by Mound related to the fabrication and sub assembly processes of the LWRHU clad hardware components. Included are details concerning configuration control systems, material procurement and certification, hardware fabrication specifics, and special processes that are utilized.

  3. Light-weight radioisotope heater unit (LWRHU) impact tests

    Science.gov (United States)

    Reimus, M. A. H.; Rinehart, G. H.; Herrera, A.; Lopez, B.; Lynch, C.; Moniz, P.

    1998-01-01

    The light-weight radioisotope heater unit (LWRHU) is a 238PuO2-fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. Los Alamos National Laboratory designed, fabricated, and safety tested the LWRHU. The heat source consists of a hot-pressed 238PuO2 fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a fineweave-pierced fabric graphite aeroshell assembly. To compare the performance of the LWRHUs fabricated for the Cassini mission with the performance of those fabricated for the Galileo mission, and to determine a failure threshold, two types of impact tests were conducted. A post-reentry impact test was performed on one of 180 flight-quality units produced for the Cassini mission and a series of sequential impact tests using simulant-fueled LWRHU capsules were conducted respectively. The results showed that deformation and fuel containment of the impacted Cassini LWRHU was similar to that of a previously tested Galileo LWRHU. Both units sustained minimal deformation of the aeroshell and fueled capsule; the fuel was entirely contained by the platinum capsule. Sequential impacting, in both end-on and side-on orientations, resulted in increased damage with each subsequent impact. Sequential impacting of the LWRHU appears to result in slightly greater damage than a single impact at the final impact velocity of 50 m/s.

  4. Energy Savings and Breakeven Costs for Residential Heat Pump Water Heaters in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-07-01

    Heat pump water heaters (HPWHs) have recently re-emerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, NREL performed simulations of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern United States. When replacing an electric water heater, the HPWH is likely to break even in California, the southern United States, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

  5. Regional Variation in Residential Heat Pump Water Heater Performance in the U.S.: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

    2014-01-01

    Residential heat pump water heaters (HPWHs) have recently reemerged on the U.S. market. These units have the potential to provide homeowners significant cost and energy savings. However, actual in use performance of a HPWH will vary significantly with climate, installation location, HVAC equipment, and hot water use. To determine what actual in use energy consumption of a HPWH may be in different regions of the U.S., annual simulations of both 50 and 80 gallon HPWHs as well as a standard electric water heater were performed for over 900 locations across the U.S. The simulations included a benchmark home to take into account interactions between the space conditioning equipment and the HPWH and a realistic hot water draw profile. It was found that the HPWH will always save some source energy when compared to a standard electric resistance water heater, although savings varies widely with location. In addition to looking at source energy savings, the breakeven cost (the net installed cost a HPWH would have to have to be a cost neutral replacement for a standard water heater) was also examined. The highest breakeven costs were seen in cases with high energy savings, such as the southeastern U.S., or high energy costs, such as New England and California. While the breakeven cost is higher for 80 gallon units than 50 gallon units, the higher net installed costs of an 80 gallon unit lead to the 50 gallon HPWHs being more likely to be cost effective.

  6. Regional Variation in Residential Heat Pump Water Heater Performance in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-01-01

    Residential heat pump water heaters (HPWHs) have recently re-emerged on the U.S. market, and they have the potential to provide homeowners significant cost and energy savings. However, actual in use performance of a HPWH will vary significantly with climate, installation location, HVAC equipment, and hot water use. To determine the actual energy consumption of a HPWH in different U.S. regions, annual simulations of both 50 and 80 gallon HPWHs as well as a standard electric water heater were performed for over 900 locations across the United States. The simulations included a benchmark home to take into account interactions between the space conditioning equipment and the HPWH and a realistic hot water draw profile. It was found that the HPWH will always save some source energy when compared to a standard electric resistance water heater, although savings varies widely with location. In addition to looking at source energy savings, the breakeven cost (the net installed cost a HPWH would have to have to be a cost neutral replacement for a standard water heater) was also examined. The highest breakeven costs were seen in cases with high energy savings, such as the southeastern U.S., or high energy costs, such as New England and California. While the breakeven cost is higher for 80 gallon units than 50 gallon units, the higher net installed costs of an 80 gallon unit lead to the 50 gallon HPWHs being more likely to be cost effective.

  7. Energy Savings and Breakeven Cost for Residential Heat Pump Water Heaters in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

    2013-07-01

    Heat pump water heaters (HPWHs) have recently reemerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, simulations were performed of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern US. When replacing an electric water heater, the HPWH is likely to break even in California, the southern US, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

  8. Light Weight Radioisotope Heater Unit (LWRHU) production for the Galileo mission

    Science.gov (United States)

    Rinehart, Gary H.

    The Light Weight Radioisotope Heater Unit (LWRHU) is a (Pu-238)O2-fueled heat source designed to provide a thermal watt of power for space missions. The LWRHU will be used to maintain the temperature of various components on the spacecraft at the required level. The heat source consists of a (Pu-238)O2-fuel pellet, a Pt-30 pct Rh capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos National Laboratory has fabricated 134 heater units which will be used on the Galileo mission.

  9. Design of high-pressure direct contact heater for promising power supply units: Experimental substantiation

    Science.gov (United States)

    Somova, E. V.; Shvarts, A. L.; Turkin, A. V.

    2016-11-01

    The results of experimental studies of superheated steam condensation on feed water jets in a highpressure, direct-contact heat exchanger are presented. Direct contact feed water heater (DCFWH) can be used in a dual-flow diagram of a steam-power unit with ultrasupercritical steam parameters (35 MPa, 700/720°C). The direct contact feed water heater is included in the flow diagram of the II circuit in a promising power unit; it provides feed water heating to 340°C in all maintenance and emergency operation modes of the unit. The reliability of the high-pressure direct contact heater operation in this flow diagram is of major importance in relation to the danger of lead solidification in the tube space of the steam generator. Technical requirements to the design of the high-pressure direct contact heater for increasing the heat exchange efficiency are formulated based on the results of earlier studies with steam-water mixture as the heating medium. The results of studies of superheated steam condensation on jets presented in this study testify that feed water is additionally heated to the required temperature at the output of the installation. The influence of initial feed water parameters (outflow velocity and temperature) on the jet heating length is elucidated. The numerical approximation of the experimental data for determination of the jet heating length in the nominal and partial power unit loads is obtained. The results of the calculations are used to simplify the design of the water-supplying element for the direct contact feed water heater. The proposed design of direct contact feed water heater is characterized by simplicity and low metal intensity, which provides the installation reliability at the considered pressure level due to the minimum number of structural elements.

  10. Using Loop Heat Pipes to Minimize Survival Heater Power for NASA's Evolutionary Xenon Thruster Power Processing Units

    Science.gov (United States)

    Choi, Michael K.

    2017-01-01

    A thermal design concept of using propylene loop heat pipes to minimize survival heater power for NASA's Evolutionary Xenon Thruster power processing units is presented. It reduces the survival heater power from 183 W to 35 W per power processing unit. The reduction is 81%.

  11. Solar hot water systems for the southeastern United States: principles and construction of breadbox water heaters

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-02-01

    The use of solar energy to provide hot water is among the easier solar technologies for homeowners to utilize. In the Southeastern United States, because of the mild climate and abundant sunshine, solar energy can be harnessed to provide a household's hot water needs during the non-freezing weather period mid-April and mid-October. This workbook contains detailed plans for building breadbox solar water heaters that can provide up to 65% of your hot water needs during warm weather. If fuel costs continue to rise, the annual savings obtained from a solar water heater will grow dramatically. The designs in this workbook use readily available materials and the construction costs are low. Although these designs may not be as efficient as some commercially available systems, most of a household's hot water needs can be met with them. The description of the breadbox water heater and other types of solar systems will help you make an informed decision between constructing a solar water heater or purchasing one. This workbook is intended for use in the southeastern United States and the designs may not be suitable for use in colder climates.

  12. Effect of Parametric Uncertainties, Variations, and Tolerances on Thermohydraulic Performance of Flat Plate Solar Air Heater

    Directory of Open Access Journals (Sweden)

    Rajendra Karwa

    2014-01-01

    Full Text Available The paper presents results of an analysis carried out using a mathematical model to find the effect of the uncertainties, variations, and tolerances in design and ambient parameters on the thermohydraulic performance of flat plate solar air heater. Analysis shows that, for the range of flow rates considered, a duct height of 10 mm is preferred from the thermohydraulic consideration. The thermal efficiency changes by about 2.6% on variation in the wind heat transfer coefficient, ±5 K variation in sky temperature affects the efficiency by about ±1.3%, and solar insolation variation from 500 to 1000 Wm−2 affects the efficiency by about −1.5 to 1.3% at the lowest flow rate of 0.01 kgs−1 m−2 of the absorber plate with black paint. In general, these effects reduce with increase in flow rate and are lower for collector with selective coating on the absorber plate surface. The tolerances in the duct height and absorber plate emissivity should be small while positive tolerance of 3° in the collector slope for winter operation and ±3° for year round operation, and a positive tolerance for the gap between the absorber plate and glass cover at nominal value of 40 mm are recommended.

  13. Solar water heater design package

    Science.gov (United States)

    1981-01-01

    Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

  14. Analysis of Ruptured Heater Tube of Degasser Condenser in Wolsong Unit 4

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Pyo; Kim, J. S.; Lim, Y. S.; Kim, S. S.; Hwang, S. S.; Kim, D. J.; Kim, S. W.; Jeong, M. K.; Hong, J. H

    2007-08-15

    In a degasser condenser in Wolsong unit 4, the cracks were found in the heater tube no. 6 and no. 7. To avoid additional damages in the specimen during a decontamination process for the previous analysis, the cracks were analyzed without any decontamination process in this work. We performed the investigation of the ruptured surface morphology, the EDS analysis of the ruptured surface, the microstructural analysis of Alloy 800H sheath tube and literature survey to find the failure mechanism. From the results, it was expected that the sheath tube has been exposed in a steam condition as the coolant level was decreased in the degasser condenser, leading to the rupture of the sheath tube.

  15. Safety analysis for the Galileo light-weight radioisotope heater unit

    Science.gov (United States)

    Johnson, Ernest W.

    The Light-Weight Radioisotope Heater Unit (LWRHU) will be used on the NASA Galileo Mission to provide thermal energy to the various systems on the orbiter and probe that are adversely affected by the low temperature a spacecraft encounters during a long interplanetary mission. Using these plutonia-fueled sources in 1-W increments permits employment of a single design and provides the spacecraft user the option of how many to use and where to position them to satisfy the proper thermal environment for components requiring such consideration. The use of the radioisotope Pu 238 in these devices necessitates the assessment of postulated radiological risks which might be experienced in case of accidents or malfunctions of the space shuttle or the spacecraft during phases of the mission in the vicinity of the earth. Included are data for the design, mission descriptions, postulated accidents with their consequences, test data, and the derived source terms and personnel exposures for the various events.

  16. The Epidemiology of Emergency Department-Treated Burn Injuries Associated with Portable Heaters in the United States, 2003-2013.

    Science.gov (United States)

    Brooks, Raina D; McGwin, Gerald

    The purpose of this study is to examine the epidemiology of portable space heater-related burn injuries among an emergency department nationally representative population of the United States. The data analyzed in this study were collected from the Consumer Products Safety Commission's 2003-2013 National Electronic Injury Surveillance System. There were approximately 53,636 space heater-related thermal burn injuries attributed to portable space heaters from 2003 to 2013. The rate of injuries was relatively constant during the 10-year span. The number of burn injuries was highest during winter months. Young children, older adults, males, and Blacks had the highest rates of injury. The body part most commonly injured was the hand, which accounted for 33.3% of all burn injuries. It is important to understand the characteristics of persons who have an increased risk of portable space heater burn and trip/fall injuries, so that preventative methods and awareness strategies can be used to help reduce the number of annual portable space heater injuries.

  17. Temperature optimization of an electric heater by emissivity variation of heating elements

    Directory of Open Access Journals (Sweden)

    Cédric Hemmer

    2014-11-01

    Full Text Available This note addresses an industrial application concerning the way to optimize the surface temperature of commercial electrical heater. The aim of this paper is to reduce the temperature on accessible surfaces and electrical heater in order to respect the European standards and quality criteria imposed by the manufacturer. This target must be achieved by changing only the emissivity distribution of the electric heater components. A numerical study of the natural convection flow coupled with radiation is carried out in a heated room with an electric heater. The physical model includes the transport equations of mass, momentum, energy and radiative transfer which are solved numerically. Thermo-physical properties of the fluid are assumed to be dependent of the temperature. The numerical simulations are carried out for a two-dimensional, steady and turbulent flow using the finite volume approach. Results showed the influence of emissivity distribution of the electric heater components. The reducing of the heating foil emissivity allowed to decrease the radiative contribution on the foil and its temperature.

  18. Radioisotope Heater Unit-Based Stirling Power Convertor Development at NASA Glenn Research Center

    Science.gov (United States)

    Wilson, Scott D.; Geng, Steven M.; Penswick, Lawrence; Schmitz, Paul C.

    2017-01-01

    Stirling Radioisotope Power Systems (RPS) are being developed as an option to provide power on future space science missions where robotic spacecraft will orbit, flyby, land or rove. A variety of mission concepts have been studied by NASA and the U. S. Department of Energy that would utilize RPS for landers, probes, and rovers and only require milliwatts to tens of watts of power. These missions would contain science measuring instruments that could be distributed across planetary surfaces or near objects of interest in space solar flux insufficient for using solar cells. A low power Stirling convertor is being developed to provide an RPS option for future low power applications. Initial concepts convert heat available from several Radioisotope Heater Units to electrical power for spacecraft instruments and communication. Initial development activity includes defining and evaluating a variety of Stirling configurations and selecting one for detailed design, research of advanced manufacturing methods that could simplify fabrication, evaluating thermal interfaces, characterizing components and subassemblies to validate design codes, and preparing for an upcoming demonstration of proof of concept in a laboratory environment.

  19. Coated particle fuel for radioisotope power systems (RPSs) and radioisotope heater units (RHUs)

    Science.gov (United States)

    Sholtis, Joseph A.; Lipinski, Ronald J.; El-Genk, Mohamed S.

    1999-01-01

    Coated particle fuel offers great promise for advanced radioisotope power systems (RPSs) and radioisotope heater units (RHUs) being pursued for future U.S. solar system exploration missions. Potential benefits of this fuel include improved design flexibility and materials compatibility, enhanced safety and performance, and reduced specific mass and volume. This paper describes and discusses coated particle fuel, with emphasis on its applicability, attributes, and potential benefits to future RPSs and RHUs. Additionally, this paper identifies further analyses and verification testing that should be conducted before a commitment is made to fully develop this fuel. Efforts to date indicate there is every reason to believe that the potential benefits of coated particle fuel to future RPSs and RHUs can be demonstrated with a modest, phased analytical and verification test effort. Thus, developmental risk appears minimal, while the potential benefits are substantial. If coated particle fuel is pursued and ultimately developed successfully, it could revolutionize the design and space use of future RPSs and RHUs.

  20. Economics of residential gas furnaces and water heaters in United States new construction market

    OpenAIRE

    Lekov, Alex B.

    2010-01-01

    New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

  1. Performance analysis of coated 238PuO2 fuel particles compact for radioisotope heater units

    Science.gov (United States)

    Tournier, Jean-Michel; El-Genk, Mohamed S.

    2000-01-01

    A fuel form consisting of coated plutonia fuel particles dispersed in a graphite matrix is being investigated for use in Radioisotope Heater Units (RHUs). The fuel particles consist of a 238PuO2 kernel (300-1200 μm in diameter), a 5-μm PyC inner coating and a ZrC outer coating (>=10 μm). The latter, an extremely strong material at high temperatures, serves as a pressure vessel for maintaining the integrity of the fuel particle and containing the helium generated by radioactive decay. Parametric analyses compared the thermal powers of the coated particle fuel compact (CPFC) RHU and LWRHU. Both utilize Fine-Weave Pierced Fabric (FWPF) aeroshell and PyC insulation sleeves. During normal operation, the fuel temperature is ~800 K, but could reach as much as 1723 K during an accidental re-entry heating. Assuming full helium release, a single-size particle (500 μm) fuel compact would maintain its integrity at a temperature of 1723 K, after 10 years storage time before launch. When replacing the LWRHU fuel pellet, Pt-alloy clad and inner PyC insulation sleeve with CPFC, the calculated thermal power of the CPFC-RHU is 1.5, 2.3 and 2.4 times that of LWRHU, for 100%, 10%, and 5% helium release, respectively, with little change in total mass. A fuel compact using binary-size particles (300 and 1200 μm diameters) would deliver 15% more thermal power. A one-dimensional, transient thermal analysis of the CPFC-RHU showed that during accidental re-entry the maximum fuel temperature in the CPFC would be 1734 K. .

  2. Coated particle fuel for radioisotope power systems and heater units: status and future research needs

    Science.gov (United States)

    El-Genk, Mohamed S.; Tournier, Jean-Michel; Sholtis, Joseph A.; Lipinski, Ronald J.

    2000-01-01

    Coated particle fuel has been proposed recently for use in Radioisotope Power Systems (RPSs) and Radioisotope Heater Units (RHUs) for a variety of space missions requiring power levels from mWs to 10's or even hundreds of Watts. It can be made into different shapes and sizes of solid compacts, heating tapes, or paints. Using a conservative design approach, this fuel form could increase by 2.3-2.4 times the thermal power output of a LWRHU, while offering promise of enhanced safety. These performance figures are based on using single-size (500 μm) compacts of ZrC coated 238PuO2 kernels and assuming 10% and 5% He release, respectively, at 1723 K, following 10 years of storage. Using binary-size (300 and 1200 μm) fuel kernels in the compact increases the thermal power output by an additional 15%. 238PuO2 fuel kernels are intentionally sized (>=300 μm in diameter) to prevent any adverse radiological effects. They are non-respirable and non-inhalable and, if ingested, would simply be excreted with no radiological effects. The 238PuO2 fuel kernels are contained within a strong ZrC coating, which is designed to fully retain the fuel and the helium gas. Helium retention in large grain (>=300 μm) granular and polycrystalline fuel kernels is possible even at high temperatures (>1700 K). The former could be fabricated using binderless agglomeration or similar processes, while the latter could be fabricated using Sol-Gel or thermal plasma processes, with potentially less radioactive waste and fabrication contamination. In addition to summarizing the results of a recent effort investigating the performance of coated fuel particle compact (CPFC) and helium gas release, this paper identifies and discusses future research and testing needs. .

  3. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Whipple, Richard E [Livermore, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  4. Performance Study of Swimming Pool Heaters

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.J.

    2009-01-01

    The objective of this report is to perform a controlled laboratory study on the efficiency and emissions of swimming pool heaters based on a limited field investigation into the range of expected variations in operational parameters. Swimming pool heater sales trends have indicated a significant decline in the number of conventional natural gas-fired swimming pool heaters (NGPH). On Long Island the decline has been quite sharp, on the order of 50%, in new installations since 2001. The major portion of the decline has been offset by a significant increase in the sales of electric powered heat pump pool heaters (HPPH) that have been gaining market favor. National Grid contracted with Brookhaven National Laboratory (BNL) to measure performance factors in order to compare the relative energy, environmental and economic consequences of using one technology versus the other. A field study was deemed inappropriate because of the wide range of differences in actual load variations (pool size), geographic orientations, ground plantings and shading variations, number of hours of use, seasonal use variations, occupancy patterns, hour of the day use patterns, temperature selection, etc. A decision was made to perform a controlled laboratory study based on a limited field investigation into the range of expected operational variations in parameters. Critical to this are the frequency of use, temperature selection, and sizing of the heater to the associated pool heating loads. This would be accomplished by installing a limited amount of relatively simple compact field data acquisition units on selected pool installations. This data included gas usage when available and alternately heater power or gas consumption rates were inferred from the manufacturer's specifications when direct metering was not available in the field. Figure 1 illustrates a typical pool heater installation layout.

  5. Thermal storage heaters

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, K.H.; Broadbent, J.T.

    1991-02-27

    A storage heater, providing heat by radiation, comprises an internal circuit for the passage of heated air. The heater comprises: a heat storage core, comprising heat storage rods heated by resistance wiring, and an air space around the rods, the air space forming an inner pathway of circuit; heat insulation around the core; and outer pathways adjacent outer walls of the heater. A damper is arranged at the top of the inner and outer pathways to control the communication between. The damper may be movably supported on a support part by robust bi-metallic strips wound with heater wires to control the bending of the strips. The storage heater may be supplied in kit form for the purchaser to assemble and to this end the heat storage rods may comprise particulate material poured into tubes, or liftable core units. Further heat insulation may be selectively positioned in the outer pathways to provide an even heat distribution. (author).

  6. Reentry response of the light weight radioisotope heater unit resulting from a Venus-Earth-Earth Gravity Assist maneuver accident

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, J.C.

    1988-10-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Light Weight Radioisotope Heater Unit for Galileo/VEEGA reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, the fuel clad, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is assumed to be recession corresponding to 50% of the wall thickness (the design criterion recommended in the DOE Overall Safety Manual). Although the analyses have been carried far beyond this limit (as presented and discussed herein), JHU/APL endorses the position that failure may occur at the time that this recession is achieved or at lower altitudes within the heat pulse considering the uncertainties in the aerodynamic, thermodynamic, and thermo-structural analyses and modeling. These uncertainties result mainly because of the high energies involved in the VEEGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact until it impacts with a clad that had been molten. 80 refs., 46 figs., 16 tabs.

  7. Estimates of helium gas release in 238PuO 2 fuel particles for radioisotope heat sources and heater units

    Science.gov (United States)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2000-06-01

    Release data of noble gases (Xe and Kr) from small-grain (7-40 μm), large-grain (⩾300 μm), and monocrystal UO 2 fuel particles, during isothermal irradiation up to 6.4 at.% and 2030 K are reviewed and their applicability to estimate helium release from 238PuO 2 fuel particles (⩾300 μm in diameter) is examined. Coated 238PuO 2 particles have recently been proposed for use in radioisotope power systems and heater units employed in planetary exploration missions. These fuel particles are intentionally sized and designed to prevent any adverse radiological effect and retain the helium gas generated by the radioactive decay of 238Pu, a desired feature for some planetary missions. Results suggest that helium release from large-grain (⩾300 μm) particles of K could be 80% but less than 7% at 1042 K, which is in general agreement with the experiments conducted at Los Alamos National Laboratory more than two decades ago. In these experiments, the helium gas release from small-grain (7-40 μm) 238PuO 2 fuel pellets has been measured during steady-state heating at temperatures up to 1886 K and ramp heating to 1723 K.

  8. 40 CFR 65.149 - Boilers and process heaters.

    Science.gov (United States)

    2010-07-01

    ... thermal units per hour) or greater. (ii) A boiler or process heater into which the vent stream is... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Boilers and process heaters. 65.149... System or a Process § 65.149 Boilers and process heaters. (a) Boiler and process heater equipment...

  9. Light-Weight Radioisotope Heater Unit final safety analysis report (LWRHU-FSAR): Volume 1: A. Introduction and executive summary: B. Reference Design Document (RDD)

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, E.W.

    1988-10-01

    The orbiter and probe portions of the National Aeronautics and Space Administration (NASA) Galileo spacecraft contain components which require auxiliary heat during the mission. To meet these needs, the Department of Energy's (DOE's) Office of Special Applications (OSA) has sponsored the design, fabrication, and testing of a one-watt encapsulated plutonium dioxide-fueled thermal heater named the Light-Weight Radioisotope Heater Unit (LWRHU). This report, prepared by Monsanto Research Corporation (MRC), addresses the radiological risks which might be encountered by people both at the launch area and worldwide should postulated mission failures or malfunctions occur, resulting in the release of the LWRHUs to the environment. Included are data from the design, mission descriptions, postulated accidents with their consequences, test data, and the derived source terms and personnel exposures for the various events. 11 refs., 44 figs., 11 tabs.

  10. Status of Hollow Cathode Heater Development for the Space Station Plasma Contactor

    Science.gov (United States)

    Soulas, George C.

    1994-01-01

    A hollow cathode-based plasma contactor has been selected for use on the Space Station. During the operation of the plasma contactor, the hollow cathode heater will endure approximately 12000 thermal cycles. Since a hollow cathode heater failure would result in a plasma contactor failure, a hollow cathode heater development program was established to produce a reliable heater. The development program includes the heater design, process documents for both heater fabrication and assembly, and heater testing. The heater design was a modification of a sheathed ion thruster cathode heater. Heater tests included testing of the heater unit alone and plasma contactor and ion thruster testing. To date, eight heaters have been or are being processed through heater unit testing, two through plasma contactor testing and three through ion thruster testing, all using direct current power supplies. Comparisons of data from heater unit performance tests before cyclic testing, plasma contactor tests, and ion thruster tests at the ignition input current level show the average deviation of input power and tube temperature near the cathode tip to be +/-0.9 W and +/- 21 C, respectively. Heater unit testing included cyclic testing to evaluate reliability under thermal cycling. The first heater, although damaged during assembly, completed 5985 ignition cycles before failing. Four additional heaters successfully completed 6300, 6300, 700, and 700 cycles. Heater unit testing is currently ongoing for three heaters which have to date accumulated greater than 7250, greater than 5500, and greater than 5500 cycles, respectively.

  11. Hollow cathode heater development for the Space Station plasma contactor

    Science.gov (United States)

    Soulas, George C.

    1993-01-01

    A hollow cathode-based plasma contactor has been selected for use on the Space Station. During the operation of the plasma contactor, the hollow cathode heater will endure approximately 12000 thermal cycles. Since a hollow cathode heater failure would result in a plasma contactor failure, a hollow cathode heater development program was established to produce a reliable heater design. The development program includes the heater design, process documents for both heater fabrication and assembly, and heater testing. The heater design was a modification of a sheathed ion thruster cathode heater. Three heaters have been tested to date using direct current power supplies. Performance testing was conducted to determine input current and power requirements for achieving activation and ignition temperatures, single unit operational repeatability, and unit-to-unit operational repeatability. Comparisons of performance testing data at the ignition input current level for the three heaters show the unit-to-unit repeatability of input power and tube temperature near the cathode tip to be within 3.5 W and 44 degrees C, respectively. Cyclic testing was then conducted to evaluate reliability under thermal cycling. The first heater, although damaged during assembly, completed 5985 ignition cycles before failing. Two additional heaters were subsequently fabricated and have completed 3178 cycles to date in an on-going test.

  12. Solar air heaters and their applications

    Science.gov (United States)

    Selcuk, M. K.

    1977-01-01

    The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.

  13. Technique of optimization of minimum temperature driving forces in the heaters of regeneration system of a steam turbine unit

    Science.gov (United States)

    Shamarokov, A. S.; Zorin, V. M.; Dai, Fam Kuang

    2016-03-01

    At the current stage of development of nuclear power engineering, high demands on nuclear power plants (NPP), including on their economy, are made. In these conditions, improving the quality of NPP means, in particular, the need to reasonably choose the values of numerous managed parameters of technological (heat) scheme. Furthermore, the chosen values should correspond to the economic conditions of NPP operation, which are postponed usually a considerable time interval from the point of time of parameters' choice. The article presents the technique of optimization of controlled parameters of the heat circuit of a steam turbine plant for the future. Its particularity is to obtain the results depending on a complex parameter combining the external economic and operating parameters that are relatively stable under the changing economic environment. The article presents the results of optimization according to this technique of the minimum temperature driving forces in the surface heaters of the heat regeneration system of the steam turbine plant of a K-1200-6.8/50 type. For optimization, the collector-screen heaters of high and low pressure developed at the OAO All-Russia Research and Design Institute of Nuclear Power Machine Building, which, in the authors' opinion, have the certain advantages over other types of heaters, were chosen. The optimality criterion in the task was the change in annual reduced costs for NPP compared to the version accepted as the baseline one. The influence on the decision of the task of independent variables that are not included in the complex parameter was analyzed. An optimization task was decided using the alternating-variable descent method. The obtained values of minimum temperature driving forces can guide the design of new nuclear plants with a heat circuit, similar to that accepted in the considered task.

  14. Design, construction, operation and evaluation of a prototype culm combustion boiler/heater unit. Technical progress report, October 1-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-02-01

    This report provides a summary of the work performed on the Prototype Culm Combustion Boiler/Heater Unit, Phase I - Engineering Design and Analysis and Limited Phase II - Prototype Plant Construction during the period October 1, 1979 through December 31, 1979. The objectives of the program as well as the technical progress and problem areas encountered are presented. Progress on the components and system engineering studies is described. The Preliminary Design of Prototype Unit Topical Report was submitted. Final design activity is continuing and the progress on drawing preparation and advanced procurement activity is discussed. Based on authorization for a limited amount of Phase II activity, initial Purchase Orders were released authorizing preparation of certified drawings for fabricated equipment required to support the Phase I final design activity. The Purchase Order for site clearance and installation of boiler foundations was awarded and ground breaking ceremonies were held at the Prototype Culm Combustion Boiler site in Paxinos, Pennsylvania, on December 7, 1979.

  15. 40 CFR 63.988 - Incinerators, boilers, and process heaters.

    Science.gov (United States)

    2010-07-01

    ... bed. (3) Where a boiler or process heater of less than 44 megawatts (150 million British thermal units... heaters. 63.988 Section 63.988 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Routing to a Fuel Gas System or a Process § 63.988 Incinerators, boilers, and process heaters....

  16. The equivalent enthalpy drop theory calculation of the ejector heaters applied for low-pressure feed water heater system of thermal power unit%引射式加热器替代低压回热系统等效焓降分析

    Institute of Scientific and Technical Information of China (English)

    杨琳; 冉景煜

    2011-01-01

    There is much exergy loss in low-pressure feed water heater system of the thermal unit.The thermo-economic characters by the equivalent enthalpy drop method while the low-pressure heater was replaced with the ejector heater.At the same time,the thermo-economic characters formulas for the different factors were also gotten.Based on these results,the thermo-economic changing features were analyzed for the low pressure heaters replaced with the ejector heaters of the N600-165/535/535 units,and the results were compared with the normal heat balance method.The results show that the ejector heaters can reduce the exergy loss efficiently,and the thermo-economic effects is the best for replacing the all low-pressure heaters with the ejector heaters,and its efficiency can be increased by 0.263%.The given equations of this paper can be used for analyzing the thermal economic effects.%火电机组低压回热系统中的面式加热器普遍存在较大损。应用等效焓降方法,深入分析采用引射式加热器替代面式低压加热器下机组热经济性的变化,并得到各个变化因素的数学计算式。在此基础上,对N600-165/535/535型机组低压回热系统进行实例计算,并与常规热平衡法计算进行了比较,结果表明:引射式加热器替代面式低压加热器,可以有效减小损,替代全部四级面式低压加热器,可使机组经济性提升最大,达0.263%;文中分析推导得出的计算表达式可用于机组热经济性分析计算。

  17. Design, construction, operation, and evaluation of a prototype culm-combustion boiler/heater unit. Quarterly technical progress report, October 1-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-01

    This report provides a summary of the work performed on the Prototype Culm Combustion Boiler/Heater Unit, Phase I - Engineering Design and Analysis and Phase II - Prototype Plant Construction during the period October 1, 1980 through December 31, 1980. The objectives of the program as well as the technical progress and problem areas encountered during the reporting period are presented. The final detail design effort was completed and the final design report submitted. Progress on procurement activity authorized by full Phase II release on March 20, 1980, is discussed. Following approval by DOE, a purchase order was placed with the Norflor Construction Corporation for the prototype plant construction which began in November. Construction of the access roadway installation of the electric power, sewer and water lines was completed during this reporting period. Boiler construction continued.

  18. Design, construction, operation and evaluation of a Prototype Culm Combustion Boiler/Heater Unit. Quarterly technical progress report, October 1-December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    1980-02-01

    This report provides a summary of the work performed on the Prototype Culm Combustion Boiler/Heater Unit, Phase I - Engineering Design and Analysis and Limited Phase II - Prototype Plant Construction during the period October 1, 1979 through December 31, 1979. The objectives of the program as well as the technical progress and problem areas encountered during the reporting period are presented. Progress on the components and system engineering studies is described. The Preliminary Design of Prototype Unit Topical Report was submitted during this reporting period. Final design activity is continuing and the progress on drawing preparation and advanced procurement activity is discussed. Based on authorization for a limited amount of Phase II activity, initial purchase orders were released authorizing preparation of certified drawings for fabricated equipment required to support the Phase I final design activity. The Purchase Order for site clearance and installation of boiler foundations was awarded during this reporting period and ground breaking ceremonies were held at the Prototype Culm Combustion Boiler site in Paxinos, Pennsylvania on December 7, 1979.

  19. Transparent electric convection heater

    OpenAIRE

    Khalid, A.; Luck, J.L.

    2001-01-01

    An optically transparent electrically heated convection heater for use as a space heater in homes, offices, shops. Typically, said convection heater consists of a transparent layer 1 upon which is deposited a layer of a transparent electrically conductive material 2 such as indium-tin-oxide, electrodes 3 and 3a are formed on opposite edges of the transparent electrically conductive layer 2 and electrical wires 4 and 4a are connected to the electrodes. The transparent electrically conductive l...

  20. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J [Bellaire, TX; Coit, William George [Bellaire, TX; Griffin, Peter Terry [Brixham, GB; Hamilton, Paul Taylor [Houston, TX; Hsu, Chia-Fu [Granada Hills, CA; Mason, Stanley Leroy [Allen, TX; Samuel, Allan James [Kular Lumpar, ML; Watkins, Ronnie Wade [Cypress, TX

    2012-07-31

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  1. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, MY); Watkins, Ronnie Wade (Cypress, TX)

    2010-11-09

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  2. Mountain Plains Learning Experience Guide: Appliance Repair. Course: Heater-Type Appliances.

    Science.gov (United States)

    Ziller, T.

    One of two individualized courses included in an appliance repair curriculum (see CE 027 767), this course covers minor and major heater-type appliances. The course is comprised of six units: (1) Irons, (2) Roasters, (3) Space Heaters, (4) Water Heaters, (5) Electric Ranges, and (6) Gas Ranges. Each unit begins with a Unit Learning Experience…

  3. Design, construction, operation, and evaluation of a prototype culm combustion boiler/heater unit. Quarterly technical progress report, October 1-December 21, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This report provides a summary of the work performed on the Prototype Culm Combustion Boiler/Heater Unit, Phase I - Engineering Design and Analysis, Phase II - Prototype Plant Construction and Phase III - Start-Up and Operation during the period October 1, 1981 through December 31, 1981. The objectives of the program as well as the technical progress and problem areas encountered during the reporting period are presented. Seven shakedown tests were run. Start-up and shakedown testing was completed. Four parametric tests were run. Performance data are presented with the exception of boiler efficiency which will be reported once chemical analyses are completed. Total boiler operation time through the end of this quarter - 1225 h, 50 min; operating time on culm and culm/limestone - 682 h, 43 min. Inspection revealed no problems with boiler tube wear. Sulfur capture greater than 94% was demonstrated (design is 88%). A turndown of better than 4 to 1 was shown (design is 2.5 to 1). Computer control of most of the loops has been successful and manual control was also demonstrated.

  4. Design of a unit to produce hot distilled water for the same power consumption as a water heater

    Science.gov (United States)

    Bambenek, R. A.; Nuccio, P. P.

    1973-01-01

    Unit recovers 97% of water contained in pretreated waste water. Some factors are: cleansing agent prevents fouling of heat transfer surface by highly concentrated waste; absence of dynamic seals reduces required purge gas flow rate; and recycle loop maintains constant flushing process to carry cleansing agent across evaporation surface.

  5. Reentry response of the lightweight radioisotope heater unit resulting from a Cassini Venus-Venus-Earth-Jupiter gravity assist maneuver accident

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    Reentry analyses consisting of ablation response, thermal response and thermal stress response have been conducted on the Lightweight Radioisotope Heater Unit (LWRHU) for Cassini/Venus-Venus-Earth-Jupiter-Gravity-Assist (VVEJGA) reentry conditions. Sequential ablation analyses of the LWRHU aeroshell, and the fuel pellet have been conducted in reentry regimes where the aeroshell has been deemed to fail. The failure criterion for ablation is generally assumed to be recession corresponding to 75% and 100% of the wall thickness. The 75% recession failure criteria allows for uncertainties that result mainly because of the high energies involved in the VVEJGA reentries compared to orbital decay reentries. Risk evaluations should consider the fact that for shallow flight paths the unit may disassemble at high-altitude as a result of ablation or may remain intact with a clad that had been molten. Within the limitations of the methodologies and assumptions of the analyses, the results indicate that: (1) For a side-on stable LWRHU reentry, aeroshell ablation failures occur for all reentry angles. (2)For a side-on spinning LWRHU reentry, aeroshell ablation failures are minimal. (3) For the tumbling LWRHU reentry, the aeroshell survives for most angles. (4) For the thermostructural analyses, using both a 1% and 5% allowable strain, all reentry angles and orientations examined resulted in small localized failures, but aeroshell breach is not predicted for any case. The analyses included in this report concentrate on VVEJGA reentry scenarios. Analyses reported previously have demonstrated that the LWRHU has adequate design margin to survive reentry from orbital decay scenarios and most injection scenarios at speeds up to escape speeds. The exception is a narrow range of flight path angles that produce multiple skip trajectories which may have excessive ablation.

  6. 600MW Supercritical Unit Heat System Heater Running Economy Analysis%600MW超临界机组回热系统加热器运行经济性分析

    Institute of Scientific and Technical Information of China (English)

    丁之淇

    2015-01-01

    通过实际测量6000MW级超临界机组高、低压加热器运行的各项参数,分析有关参数对机组经济性定量影响,并且对高、低压加热器运行经济性进行了分析和评估,同时提出了高、低压加热器水位调整的的试验准备、试验方法、热控定值修改等技术措施和建议,提高机组运行经济性。%Through the 6000 MW supercritical unit level high and low heater operation of the variousparame⁃ters, an analysis of the parameters quantitative influence on the unit economy, and the high and low heater running economy are analyzed and evaluated, at the same time puts forward the high and low heater water level adjustment test preparation, test method, thermal control fixed value modification and other technical measures and Suggestions for manufacturing and operation maintenance unit reference.

  7. Failure Analysis of Drainage System Under the LP Heater in A 600MW Unit%600MW机组低压加热器疏水系统故障原因浅析

    Institute of Scientific and Technical Information of China (English)

    王波; 吴喜

    2012-01-01

    某600MW机组低压加热器系统由于原设计缺陷,在机组升负荷过程中,其6号低加至7号低加正常疏水逐级自流不畅,使机组冷源损失增大,直接影响了机组热经济性.通过详细分析并加以实验验证,找到了导致低加疏水系统故障的根本原因,提出了技术改造方案以供工程应用参考.%Because the original design of drainage system under the LP heater system in a 600MW unit was defective, it resulted the gravity step by step of the normal drainage from 6 LP heater to 7 LP heater was poor when the unit load was increasing. It increased the cold source loss and directly impacted on the thermal economy of the unit. By careful analysis and experimental verification, the essential reasons leading to drainage system failure had been found and technological transformation programs had been proposed for engineering reference.

  8. Heater Validation for the NEXT-C Hollow Cathodes

    Science.gov (United States)

    Verhey, Timothy R.; Soulas, George C.; Mackey, Jonathan Ar.

    2017-01-01

    Swaged cathode heaters whose design was successfully demonstrated under a prior flight project are to be provided by the NASA Glenn Research Center for the NEXT-C ion thruster being fabricated by Aerojet Rocketdyne. Extensive requalification activities were performed to validate process controls that had to be re-established or revised because systemic changes prevented reuse of the past approaches. A development batch of heaters was successfully fabricated based on the new process controls. Acceptance and cyclic life testing of multiple discharge and neutralizer sized heaters extracted from the development batch was initiated in August, 2016, with the last heater completing testing in April, 2017. Cyclic life testing results substantially exceeded the NEXT-C thruster requirement as well as all past experience for GRC fabricated units. The heaters demonstrated ultimate cyclic life capability of 19050 to 33500 cycles. A qualification batch of heaters is now being fabricated using the finalized process controls. A set of six heaters will be acceptance and cyclic tested to verify conformance to the behavior observed with the development heaters. The heaters for flight use will be then be provided to the contractor. This paper summarizes the fabrication process control activities and the acceptance and life testing of the development heater units.

  9. A roadmap for the development and validation of coated particle fuel for future space radioisotope heater units (RHUs) and radioisotope power systems (RPSs)

    Science.gov (United States)

    Sholtis, Joseph A.

    2001-02-01

    In early 1999, coated particle fuel was identified as offering promising advancements in design flexibility, performance, specific mass and volume, as well as safety for future space radioisotope heater units (RHUs) and radioisotope power systems (RPSs). Subsequent study, conducted during Fiscal Year 1999, provided confidence that these potential benefits were substantial and demonstrable if a modest follow-on investigative test effort was pursued. This paper lays out a roadmap for both immediate and near-term decision making, as well as any full-scale development and validation of coated particle fuel undertaken for future space RHUs, and RPSs. In an effort to obtain adequate and timely information at a reasonable cost for immediate and near-term decision making, as well as any subsequent development, production, and application decisions, a four-phased regimen of testing is identified. The four phases of testing are: (1) Pre-Decisional Testing: (2) Pre-Production Analytical Verification Testing: (3) Production Quality Assurance Testing: and (4) Post-Production Safety Verification Testing. Although all four of these phases of testing are considered essential, the first two phases are especially important for immediate and near-term decisions to advance and pursue coated particle fuel for space RHUs and RPSs. The third and fourth phases of testing are primarily identified and included for completeness at this early stage. It is concluded that there is every reason to believe that the potential benefits of coated particle fuel can be readily demonstrated through a modest investigative test effort. If such an effort is pursued and proves successful, coated particle fuel could then be developed with assurance that its ultimate benefits would revolutionize the design and space use of future RHUs and RPSs. It is hoped that this paper will serve as a starting point for further discussions and more specific planning activities aimed at advancing coated particle fuel for

  10. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  11. Artificial electron heating of winter mesospheric radar clouds (PMWE) and the interpretation of the radar backscatter variation during the heater cycling.

    Science.gov (United States)

    Kassa Bekele, Meseret; Havnes, Ove; La Hoz, Cesar; Baroni, Giovanni; Rietveld, Mike; Biebricher, Alexander

    The effect of artificial electron heating (in our case with the EISCAT Heating Facility) on the Polar Mesospheric Winter Echoes (PMWE) the weak radar clouds which occur in the winter mesosphere between heights 55 to 80 km, is normally different from its effect on the much stronger Polar Mesospheric Summer Echoes (PMSE) which occur between 80 and 90 km height. They both show a weakening of the backscatter when the heater is switched on, sometimes close to extinguishing of the radar backscatter, signaling that the increased electron pressure has smoothed the electron density gradients which are responsible for the coherent backscatter. However, while the PMSE backscatter very often show a considerable recovery during the 20 sec the heater (normally) is on and dust particles are charged more negatively by the heated electrons, this recovery is at best very weak for PMWE. The PMWE also have weak overshoots, where the backscatter flares up only by a factor 1.1 to 1.2 when the heater is switched off, compared to the undisturbed PMWE backscatter before the heater was switched on. For PMSE the overshoot factor can be as high as 7. This demonstrate that if dust particles control the PMWE their sizes must be much smaller than the PMSE particles. Modeling has shown that the likely PMWE dust sizes are in the range 3-4 nanometer making it probable that PMWE is associated with the small meteoric smoke particles. When the heater is switched off the charge of the dust particles and the intensity of the backscatter relax back to its undisturbed values. If the decharging mechanism was the same for the larger PMSE and the small PMWE dust particles one would expect a very much longer relaxation time for the PMWE than for the PMSE. The fact that the PMWE relaxation time is comparable to the PMSE show that the small meteoric dust particles must be de-charged by a more effective mechanism than ion attachment. We find that the photodetachment effect where photons of energy less than the

  12. Measure Guideline: Transitioning to a Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K.; Rapport, A.

    2012-09-01

    This Measure Guideline provides information to help residential builders and retrofitters with the design, specification, selection, implementation, installation, and maintenance issues of transitioning from tank-type water heaters to tankless water heaters. The report compares the differences between tankless and tank-type water heaters, highlighting the energy savings that can be realized by adopting tankless water heaters over tank-type water heaters. Selection criteria and risks discussed include unit sizing and location, water distribution system, plumbing line length and diameter, water quality, electrical backup, and code issues. Cost and performance data are provided for various types of tankless and tank-type water heaters, both natural gas fired and electric. Also considered are interactions between the tankless water heater and other functional elements of a house, such as cold water supply and low-flow devices. Operating costs and energy use of water distribution systems for single- and two-story houses are provided, along with discussion of the various types of distribution systems that can be used with tankless water heaters. Finally, details to prepare for proper installation of a tankless water heater are described.

  13. International shipment of light weight radioisotopic heater units (LWRHU) using the USA/9516/B(U)F Mound 1 kW shipping package in support of the ``Pluto Express'' mission

    Science.gov (United States)

    Barklay, Chadwick D.; Merten, C. William

    1997-01-01

    Radioisotopes have provided heat that has been used to maintain specific operating environments within remote satellites and spacecraft. For the ``Pluto Express'' mission the 238PuO2 fueled light weight radioisotopic heater unit (LWRHU) will be used within the spacecraft. Since the current plan for the ``Pluto Express'' mission incorporates the use of a Russian launch platform for the spacecraft, the LWRHUs must be transported in an internationally certified shipping container. An internationally certified shipping package that is versatile enough to be reconfigured to transport the LWRHUs that will be required to support the ``Pluto Express'' mission is the Mound USA/9516/B(U)F.

  14. Coaxial Electric Heaters

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

    2008-01-01

    Coaxial electric heaters have been conceived for use in highly sensitive instruments in which there are requirements for compact heaters but stray magnetic fields associated with heater electric currents would adversely affect operation. Such instruments include atomic clocks and magnetometers that utilize heated atomic-sample cells, wherein stray magnetic fields at picotesla levels could introduce systematic errors into instrument readings. A coaxial electric heater is essentially an axisymmetric coaxial cable, the outer conductor of which is deliberately made highly electrically resistive so that it can serve as a heating element. As in the cases of other axisymmetric coaxial cables, the equal magnitude electric currents flowing in opposite directions along the inner and outer conductors give rise to zero net magnetic field outside the outer conductor. Hence, a coaxial electric heater can be placed near an atomic-sample cell or other sensitive device. A coaxial electric heater can be fabricated from an insulated copper wire, the copper core of which serves as the inner conductor. For example, in one approach, the insulated wire is dipped in a colloidal graphite emulsion, then the emulsion-coated wire is dried to form a thin, uniform, highly electrically resistive film that serves as the outer conductor. Then the film is coated with a protective layer of high-temperature epoxy except at the end to be electrically connected to the power supply. Next, the insulation is stripped from the wire at that end. Finally, electrical leads from the heater power supply are attached to the exposed portions of the wire and the resistive film. The resistance of the graphite film can be tailored via its thickness. Alternatively, the film can be made from an electrically conductive paint, other than a colloidal graphite emulsion, chosen to impart the desired resistance. Yet another alternative is to tailor the resistance of a graphite film by exploiting the fact that its resistance

  15. Application of electric heater reheat technology on sulfur recovery unit%电加热器再热技术在硫磺回收装置上的应用

    Institute of Scientific and Technical Information of China (English)

    王小强; 邱斌; 赵柳鉴; 高健文; 陈亮; 田梦雯; 黄暄

    2014-01-01

    根据重庆天然气净化总厂綦江分厂硫磺回收装置的运行现状与特点,对过程气再热方式进行了选择。分析了高温掺和法、在线加热炉加热法、蒸汽加热法、气-气换热法、电加热法的优缺点,确定采用能源供应方便,结构紧凑,自动控制温度,操作简便,无污染的电加热器进行过程气再热。结论表明,在硫磺回收装置低负荷运行的条件下,过程气采用电加热技术,可确保系统温度在正常范围内,使硫磺回收装置运转正常。同时,对电加热器设备运行的常见问题和异常情况进行了分析和总结。%Aiming at current situations and characteristics of the sulfur recovery unit in Qijiang Branch ,the process gas reheating methods were determined .The advantages and disadvantages of five kinds of reheat methods technology were analyzed including high temperature mixed ,re-heating furnaces ,steam heating ,gas-gas heat exchanger and electric heater .T he electric heater was finally determined because of the advantage of convenient energy service ,compact structure , automatic temperature control ,simple operation and no pollution .The Results showed that sys-tem temperature was in normal range and sulfur recovery unit ran properly when the sulfur re-covery unit operated at low load .Meanwhile ,the common problems and abnormal situations of electric heater were analyzed and summarized .

  16. Assessing the Energy Savings of Tankless Water Heater Retrofits in Public Housing

    Energy Technology Data Exchange (ETDEWEB)

    Ries, R.; Walters, R.; Dwiantoro, D.

    2013-01-01

    This report describes the methodology, analysis, and findings from a case study of a 110 unit retrofit of gas tankless water heaters in a hot/humid climate in Alachua County, Florida. The housing units had their gas-fired tank type water heaters replaced with gas-fired tankless water heaters as part of a federal program that targeted reduced energy use in public housing.

  17. Assessing the Energy Savings of Tankless Water Heater Retrofits in Public Housing

    Energy Technology Data Exchange (ETDEWEB)

    Ries, R. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team; Walters, R. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team; Dwiantoro, D. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team

    2013-01-01

    This report describes the methodology, analysis, and findings from a case study of a 110 unit retrofit of gas tankless water heaters in a hot/humid climate in Alachua County, Florida.The gas-fired tank type water heaters in the housing units were replaced with gas-fired tankless water heaters as part of a federal program that targeted reduced energy use in public housing.

  18. International shipment of light weight radioisotopic heater units (LWRHU) using the USA/9516/B(U)F Mound 1 kW shipping package in support of the {open_quotes}Pluto Express{close_quotes} mission

    Energy Technology Data Exchange (ETDEWEB)

    Barklay, C.D. [EGG Mound Applied Technologies P.O. Box 3000 Miamisburg, Ohio45343-3000 (United States); Merten, C.W. [Mound Engineering and Analysis Group, Inc. 720 Mound Road COS Building 4222 Miamisburg, Ohio45342 (United States)

    1997-01-01

    Radioisotopes have provided heat that has been used to maintain specific operating environments within remote satellites and spacecraft. For the {open_quotes}Pluto Express{close_quotes} mission the {sup 238}PuO{sub 2} fueled light weight radioisotopic heater unit (LWRHU) will be used within the spacecraft. Since the current plan for the {open_quotes}Pluto Express{close_quotes} mission incorporates the use of a Russian launch platform for the spacecraft, the LWRHUs must be transported in an internationally certified shipping container. An internationally certified shipping package that is versatile enough to be reconfigured to transport the LWRHUs that will be required to support the {open_quotes}Pluto Express{close_quotes} mission is the Mound USA/9516/B(U)F. {copyright} {ital 1997 American Institute of Physics.}

  19. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  20. Analysis of Leak and Plugging Condition for Feedwater Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansul; Kang, Yeon Kwan; Heo, Gyunyoung [Kyung Hee University, Yongin (Korea, Republic of); Song, Seok Yoon; Oh, Seung Hwan [Korea Hydro and Nuclear Power, Daejeon (Korea, Republic of)

    2015-10-15

    Tube damage in feedwater heater occurs from damaged pressure boundary, inflow of foreign substances, erosion and corrosion. Once a heat tube is damaged, the water jet from the damaged spot is spread out to surrounding tubes. Since a feedwater heater is operated under 2-phase flow condition and has physically complicated structure, it cannot be approached on shell side. Therefore, test and inspection to check tube degradation is relatively difficult. Even though tube leak does not affect surrounding tubes, it obviously affects efficiency of turbine cycle and reduces economic feasibility in the long run. For this reason, systematic management is required on thermal performance for feedwater heaters. In this paper, PEPSE (Performance Evaluation of Power System Efficiency), one of the generic-purpose power plant simulation program, was used to construct a heat balance model for turbine cycle. The model was used to analyze the effect of change in key variables related to thermal performance of feedwater heater on turbine cycle, thereby preparing a thermal performance management strategy for feedwater heaters. Study was conducted on 6 units that represent each reactor type among domestic nuclear power plants (NPPs) in operation, but this paper described the results of high pressure feedwater heaters in a Korean standard NPP, which shows high possibility of tube damage due to large shell-tube pressure difference. In this paper, the heat balance models for turbine cycle were constructed as a part of effort to develop the thermal performance management system for feedwater heaters in NPPs.

  1. Policy Variation among Japan, Korea, England and the United States

    Directory of Open Access Journals (Sweden)

    Jaekyung Lee

    2001-04-01

    Full Text Available School reform initiatives during the last two decades in Japan, Korea, England, and the United States can be understood as balancing acts. Because policymakers in England and the United States saw their school systems fragmented and student outcomes mediocre, they focused reform efforts on raising educational standards, tightening curriculum and assessment, and improving academic achievement. In contrast, policymakers in Japan and Korea, who saw their school systems overstandardized and educational processes deficient, focused their reform efforts on deregulating schools, diversifying curriculum and assessment, and enhancing whole-person education. While school reform policies were formulated and adopted in response to each country’s unique problems, they also were driven by globalization forces that fostered an international perspective. If implemented successfully, such cross-cultural policy variations (i.e., standardization vs. differentiation in curriculum, unification vs. diversification in assessment, and privatization vs. democratization in governance would make distinctive educational systems more alike. Cultural and institutional barriers to educational convergence between the Eastern and Western school systems are discussed.

  2. Subsurface heaters with low sulfidation rates

    Energy Technology Data Exchange (ETDEWEB)

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  3. Solar water heater for NASA's Space Station

    Science.gov (United States)

    Somers, Richard E.; Haynes, R. Daniel

    1988-01-01

    The feasibility of using a solar water heater for NASA's Space Station is investigated using computer codes developed to model the Space Station configuration, orbit, and heating systems. Numerous orbit variations, system options, and geometries for the collector were analyzed. Results show that a solar water heater, which would provide 100 percent of the design heating load and would not impose a significant impact on the Space Station overall design is feasible. A heat pipe or pumped fluid radial plate collector of about 10-sq m, placed on top of the habitat module was found to be well suited for satisfying water demand of the Space Station. Due to the relatively small area required by a radial plate, a concentrator is unnecessary. The system would use only 7 to 10 percent as much electricity as an electric water-heating system.

  4. Engineering solutions for polymer composites solar water heaters production

    Science.gov (United States)

    Frid, S. E.; Arsatov, A. V.; Oshchepkov, M. Yu.

    2016-06-01

    Analysis of engineering solutions aimed at a considerable decrease of solar water heaters cost via the use of polymer composites in heaters construction and solar collector and heat storage integration into a single device representing an integrated unit results are considered. Possibilities of creating solar water heaters of only three components and changing welding, soldering, mechanical treatment, and assembly of a complicate construction for large components molding of polymer composites and their gluing are demonstrated. Materials of unit components and engineering solutions for their manufacturing are analyzed with consideration for construction requirements of solar water heaters. Optimal materials are fiber glass and carbon-filled plastics based on hot-cure thermosets, and an optimal molding technology is hot molding. It is necessary to manufacture the absorbing panel as corrugated and to use a special paint as its selective coating. Parameters of the unit have been optimized by calculation. Developed two-dimensional numerical model of the unit demonstrates good agreement with the experiment. Optimal ratio of daily load to receiving surface area of a solar water heater operating on a clear summer day in the midland of Russia is 130‒150 L/m2. Storage tank volume and load schedule have a slight effect on solar water heater output. A thermal insulation layer of 35‒40 mm is sufficient to provide an efficient thermal insulation of the back and side walls. An experimental model layout representing a solar water heater prototype of a prime cost of 70‒90/(m2 receiving surface) has been developed for a manufacturing volume of no less than 5000 pieces per year.

  5. Firebox modeling of SRT cracking heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, K.M.; Albano, J.V. [ABB Lummus Crest Inc., Bloomfield, NJ (United States)

    1994-12-31

    Thermal cracking of hydrocarbons remains the most economically attractive route for the production of ethylene. The heat for the endothermic cracking reaction is supplied in high capacity fired heaters which are designed specifically to have high selectivity to olefins. In the cracking process, coke is deposited within the tubes of the radiant coil. The rate of coke deposition in a cracking furnace is a function not only of process conditions but of other factors as well. High tube metal temperatures in certain areas of the coil or hot spots can cause locally high coking rate leading to partial blockage of the tubes and consequently, short runs. The small diameter tubes used in modern high selectivity heaters are more sensitive than older large tube designs. The occurrence of these hot zones is a strong function of fireside conditions. For satisfactory performance, the heat flux profile in a cracking heater must be maintained as uniform as possible. In addition, it is important to minimize the variation of process temperatures entering the various cracking coils. These fireside variables are not only a function of the type of burners, excess air, type of fuel(s) and distribution of air and fuel but depend significantly on the air and flue gas flow patterns associated with the firebox, i.e., the firebox aerodynamics. Poor aerodynamics can adversely affect firing patterns and hence heat flux profiles in commercial furnaces. A variety of modeling techniques have been used to evaluate the firebox aerodynamics of Lummus, Short Residence Time, cracking heaters. These include flow visualization, physical cold flow modeling, and computational techniques. These approaches are discussed in this paper.

  6. 46 CFR 119.320 - Water heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Water heaters. 119.320 Section 119.320 Shipping COAST... Machinery § 119.320 Water heaters. (a) A water heater must meet the requirements of Parts 53 and 63 in... electric water heater is also acceptable if it: (1) Has a capacity of not more than 454 liters (120...

  7. 46 CFR 182.320 - Water heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Water heaters. 182.320 Section 182.320 Shipping COAST...) MACHINERY INSTALLATION Auxiliary Machinery § 182.320 Water heaters. (a) A water heater must meet the...), except that an electric water heater is also acceptable if it: (1) Has a capacity of not more than...

  8. Thermal behavior of a porous electric heater

    Energy Technology Data Exchange (ETDEWEB)

    Naji, M.; Al-Nimr, M.A. [Jordan University of Science and Technology, Irbid (Jordan). Dept. of Mechanical Engineering

    2002-03-01

    The performance of a proposed porous electric heater is investigated. The porous heater exchanges heat with the working fluid through its large volumetric surface area. As a result, it produces lower surface temperature as compared with the conventional heater for the same imposed heating power. Two mathematical models are presented to describe the thermal behavior of both heaters. Axial diffusion is included in the governing equation of the solid conventional heater. The predictions of both models are compared at different operating conditions where it is found that porous heaters have much better thermal performance than the conventional heaters. (author)

  9. ENERGY STAR Certified Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Water Heaters that are effective April 16, 2015....

  10. Heater head for stirling engine

    Science.gov (United States)

    Corey, John A.

    1985-07-09

    A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

  11. 40 CFR 63.7491 - Are any boilers or process heaters not subject to this subpart?

    Science.gov (United States)

    2010-07-01

    ...., hazardous waste boilers). (e) A commercial and industrial solid waste incineration unit covered by 40 CFR... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial... process heaters not subject to this subpart? The types of boilers and process heaters listed in paragraphs...

  12. 76 FR 28662 - Industrial, Commercial, and Institutional Boilers and Process Heaters and Commercial and...

    Science.gov (United States)

    2011-05-18

    ... AGENCY 40 CFR Parts 60 and 63 RIN 2060-AQ25; 2060-AO12 Industrial, Commercial, and Institutional Boilers and Process Heaters and Commercial and Industrial Solid Waste Incineration Units AGENCY: Environmental... Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters'' and ``Standards...

  13. Contamination during production of heater-cooler units by Mycobacterium chimaera potential cause for invasive cardiovascular infections: results of an outbreak investigation in Germany, April 2015 to February 2016.

    Science.gov (United States)

    Haller, Sebastian; Höller, Christiane; Jacobshagen, Anja; Hamouda, Osamah; Abu Sin, Muna; Monnet, Dominique L; Plachouras, Diamantis; Eckmanns, Tim

    2016-04-28

    Invasive infections with Mycobacterium chimaera were reported in patients with previous open chest surgery and exposure to contaminated heater-cooler units (HCUs). We present results of the surveillance of clinical cases and of contaminated HCUs as well as environmental investigations in Germany up until February 2016. Clinical infections occurred in five male German cases over 50 years of age (range 53-80). Cases had been exposed to HCUs from one single manufacturer during open chest surgery up to five years prior to onset of symptoms. During environmental investigations, M. chimaera was detected in samples from used HCUs from three different countries and samples from new HCUs as well as in the environment at the manufacturing site of one manufacturer in Germany. Our investigation suggests that at least some of the M. chimaera infections may have been caused by contamination of HCUs at manufacturing site. We recommend that until sustainable measures for safe use of HCUs in operation theatres are implemented, users continue to adhere to instructions for use of HCUs and Field Safety Notices issued by the manufacturer, implement local monitoring for bacterial contamination and continuously check the websites of national and European authorities for current recommendations for the safe operation of HCUs.

  14. Our Environment in Hot Water: Comparing Water Heaters, A Life Cycle Approach Comparing Tank and Tankless Water Heaters in California

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Alison; McMahon, James; Masanet, Eric; Lutz, Jim

    2008-08-13

    Residential water heating is a large source of energy use in California homes. This project took a life cycle approach to comparing tank and tankless water heaters in Northern and Southern California. Information about the life cycle phases was calculated using the European Union's Methodology study for EcoDesign of Energy-using Products (MEEUP) and the National Renewable Energy Laboratory's Life Cycle Inventory (NREL LCI) database. In a unit-to-unit comparison, it was found that tankless water heaters would lessen impacts of water heating by reducing annual energy use by 2800 MJ/year (16% compared to tank), and reducing global warming emissions by 175 kg CO2 eqv./year (18% reduction). Overall, the production and combustion of natural gas in the use phase had the largest impact. Total waste, VOCs, PAHs, particulate matter, and heavy-metals-to-air categories were also affected relatively strongly by manufacturing processes. It was estimated that tankless water heater users would have to use 10 more gallons of hot water a day (an increased usage of approximately 20%) to have the same impact as tank water heaters. The project results suggest that if a higher percentage of Californians used tankless water heaters, environmental impacts caused by water heating would be smaller.

  15. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Davis Energy Group, Davis, CA (United States); Weitzel, Elizabeth [Davis Energy Group, Davis, CA (United States); Backman, Christine [Davis Energy Group, Davis, CA (United States)

    2017-02-28

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  16. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-02-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  17. Quench Heater Studies for the LHC Magnets

    CERN Document Server

    Rodríguez-Mateos, F

    2001-01-01

    About 2000 LHC (CERN's Large Hadron Collider) superconducting magnets will be protected with quench heaters against development of excessive voltage and overheating after a resistive transition. The quench heater strips are powered by capacitor bank discharge power supplies. The strips are made of stainless steel partially plated with copper to reduce their resistance and to allow for the connection of quench heaters in series. The strips are embedded in between two polyimide foils. The initial power density and the current decay time determine the quench heater effectiveness. Since only one type of heater power supply will be available, the copper plating cycle is adapted for the various magnet types to keep the resistance of the heater circuit constant. Different quench heater designs have been tested on various prototype magnets to optimise the copper-plating cycle and the electric insulation of the heater strip. This paper summarises the experimental results and computations that allowed to finalise the h...

  18. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  19. Comparative performance of coriander dryer coupled to solar air heater and solar air-heater-cum-rockbed storage

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, P.M.; Choudhury, C.; Garg, H.P. [Indian Inst. of Technology, Centre for Energy Studies, New Delhi (India)

    1996-03-01

    In the present communication, efforts have been made to study the drying characteristics of coriander in a stationary 0.5 tonne/batch capacity deep-bed dryer coupled to a solar air heater and a rockbed storage unit to receive hot air during sunshine and off-sunshine hours, respectively. The drying bed was assumed to consist of a number of thin layers of grains stacked upon each other. The theoretical investigation was made by writing the energy and mass balance equations for different components of the dryer-cum-air-heater-cum-storage and by adopting a finite difference approach for simulation. (author)

  20. Shared savings gets realtor new water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, R.

    1983-08-08

    The Grenadier Realty Co. of New York is financing four energy-efficient water heaters for apartment buildings with a shared savings arrangement. The arrangement allows Grenadier to avoid front-end costs, which were paid by Independent Water Heaters Inc. in exchange for a decreasing share of the savings. Grenadier will own the heaters when the five-year contract expires. By allowing a shutdown of boilers during the summer months, the heaters will further increase energy savings. (DCK)

  1. The performance of porous electric heaters

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nimr, M.A.; Naji, M.

    2003-03-01

    The performance of a proposed porous electric heater is investigated. The porous heater exchanges heat with the working fluid through its large volumetric surface area. As a result, it produces lower surface temperature as compared with the conventional heater for the same imposed heating power. Two mathematical models are presented to describe the thermal behavior of both heaters and the predictions of both models are compared at different operating conditions. (author)

  2. 14 CFR 27.833 - Heaters.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heaters. 27.833 Section 27.833 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Heaters. Each combustion heater must be approved. Fire Protection ...

  3. 14 CFR 29.833 - Heaters.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heaters. 29.833 Section 29.833 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Heaters. Each combustion heater must be approved. Fire Protection ...

  4. Mutagenicity of organic emissions from unvented kerosene heaters in a chamber study.

    Science.gov (United States)

    Mumford, J L; Lewtas, J; Williams, K; Tucker, W G; Traynor, G W

    1992-06-01

    A study was conducted to assess the mutagenicity of semivolatile organics and particle-bound organics emitted from unvented kerosene space heaters. The units tested included a well-tuned radiant heater and a maltuned convective heater. The tests were conducted in a 27-m3 chamber with a prescribed on/off heater usage pattern. The organic emissions were collected on Teflon-coated glass filters backed by XAD-2 resin. The dichloromethane-extractable organics from both the filters and the XAD were analyzed for nitropolycyclic hydrocarbons using gas chromatography/mass spectrometry, and were bioassayed for mutagenicity in microsuspension assays using Salmonella typhimurium strains TA98 with and without S9 and TA98NR (a nitroreductase-deficient strain) without S9. The results showed that both the semivolatile and particle-bound organics emitted from the kerosene heaters were mutagenic, and the presence of nitropolycyclic hydrocarbons in these organic emissions substantiated these findings.

  5. Mitochondrial DNA control region variation in Dubai, United Arab Emirates.

    Science.gov (United States)

    Alshamali, Farida; Brandstätter, Anita; Zimmermann, Bettina; Parson, Walther

    2008-01-01

    249 entire mtDNA control region sequences were generated and analyzed in a population sample from Dubai, one of the seven United Arab Emirates. The control region was amplified in one piece and sequenced with different sequencing primers. Sequence evaluation was performed twice and validated by a third senior mtDNA scientist. Phylogenetic analyses were used for quality assurance purposes and for the determination of the haplogroup affiliation of the samples. Upon publication, the population data are going to be available in the EMPOP database (www.empop.org).

  6. Test Format and the Variation of Gender Achievement Gaps within the United States

    Science.gov (United States)

    Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia

    2016-01-01

    Prior research demonstrates the existence of gender achievement gaps and the variation in the magnitude of these gaps across states. This paper characterizes the extent to which the variation of gender achievement gaps on standardized tests across the United States can be explained by differing state accountability test formats. A comprehensive…

  7. Cross-cultural variation in gelotophobia within the United States

    Directory of Open Access Journals (Sweden)

    Martin D. Lampert

    2010-06-01

    Full Text Available In the first international study of gelotophobia (the fear of being laughed at, Proyer et al. (2009 administered an established measure of gelotophobia, the GELOPH, to 93 different samples across 73 countries, including six samples from the United States. In the original study, the researchers reported notable response similarities across a core set of GELOPH items, referred to as the GELOPH. The present study takes a closer look at ethnic differences within these original United States samples, focusing specifically on the differences between European and Asian American respondents to two types of items on the GELOPH, which we identified as self-perception and social reaction items. Based on prior research dealing with self-concept and social anxiety, we predicted that individuals with a more interdependent self-construal (Asian Americans would be more likely than those with an independent self-construal (European Americans to report greater concern over revealing themselves as foolish or ridiculous in public. However, because of the greater importance for their own self concept to maintain positive social relations, Asian Americans would not be more likely than European Americans to report greater avoidance of or discomfort with social encounters involving laughter. Comparisons of the GELOPH items related to self-perceptions and social reactions supported these expectations, and we discuss how these results highlight how sets of items on the GELOPH may vary in their sensitivity to cultural differences.

  8. Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Hudon, K.; Christensen, D.

    2014-06-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt(tm) whole-house building simulations.

  9. Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Hudon, K.; Christensen, D.

    2014-06-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of U.S. climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt™ whole-house building simulations.

  10. Welding shield for coupling heaters

    Science.gov (United States)

    Menotti, James Louis

    2010-03-09

    Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

  11. Space Station solar water heater

    Science.gov (United States)

    Horan, D. C.; Somers, Richard E.; Haynes, R. D.

    1990-01-01

    The feasibility of directly converting solar energy for crew water heating on the Space Station Freedom (SSF) and other human-tended missions such as a geosynchronous space station, lunar base, or Mars spacecraft was investigated. Computer codes were developed to model the systems, and a proof-of-concept thermal vacuum test was conducted to evaluate system performance in an environment simulating the SSF. The results indicate that a solar water heater is feasible. It could provide up to 100 percent of the design heating load without a significant configuration change to the SSF or other missions. The solar heater system requires only 15 percent of the electricity that an all-electric system on the SSF would require. This allows a reduction in the solar array or a surplus of electricity for onboard experiments.

  12. Starch gelatinization in coiled heaters.

    Science.gov (United States)

    Kelder, J D H; Ptasinski, K J; Kerkhof, P J A M

    2004-01-01

    A gelatinizing model food derived from a 5% w/w cross-linked waxy maize starch suspension was simulated in coiled heaters to assess the impact of centrifugal forces on flow and heat transfer. For four coil diameters (D = 0.25, 1, 2.5, and infinity m) and three flow rates (w = 0.5, 1, and 2 m/s), heat transfer, viscous development, and the severity of channeling were evaluated. Increasing curvature proved to suppress channeling as a result of more uniform heating and gelatinization. The maximum attainable viscosity was also higher, implying a lower starch consumption for a target viscosity. Higher flow rates necessitated longer heaters, and the maximum viscosity decreased. Moderate product velocities are therefore recommended.

  13. Experimental characteristics of vortex heaters

    Science.gov (United States)

    Piralishvili, Sh. A.; Novikov, N. N.

    The performance of a Ranque-Hilsch vortex tube is investigated experimentally for the case where the tube operates as a heater, with the mass of the heated gas remaining constant. The results obtained indicate that energy separation zones with sufficiently high (50 percent) relative heating effects can be achieved for a gas flow ratio of unity. A nomogram is presented for calculating the relative and absolute heating effects as a function of the tube geometry.

  14. Graphite/Epoxy Deicing Heater

    Science.gov (United States)

    Hung, Ching-Cheh; Dillehay, Michael E.; Stahl, Mark

    1988-01-01

    Heat applied close to surface protected. One ply of highly electrically- and thermally-conductive brominated-graphite fiber composite laminated between two plies of electrically-insulating composite material, with michel foil making contact with end portions of graphite fibers. Part of foil exposed beyond composite to serve as electrical contact. Graphite/Epoxy composite heater developed to prevent and reverse formation of ice on advanced composite surfaces of aircraft.

  15. Near-surface heater experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, L.D.; Cuderman, J.F.; Krumhansl, J.L.; Lappin, A.

    1978-12-31

    Full-scale near-surface heater experiments are presently being conducted by Sandia Laboratories in the Conasauga Formation at Oak Ridge, Tennessee, and in the Eleana Formation on the Nevada Test Site, Nevada. The purposes of these experiments are: (1) to determine if argillaceous media can withstand thermal loads characteristic of high level waste; (2) to provide data for improvement of themomechanical modeling of argillaceous rocks; (3) to identify instrumentation development needed for further in situ testing; and (4) to identify unexpected general types of behavior, if any. The basic instrumentation of these tests consists of a heater in a central hole, surrounded by arrays of holes containing various instrumentation. Temperatures, thermal profiles, vertical displacements, volatile pressurization, and changes in in situ stresses are measured in each experiment as a function of time, and compared with pretest modeling results. Results to date, though in general agreement with modeling results assuming conductive heat transfer within the rock, indicate that the presence of even small amounts of water can drastically affect heat transfer within the heater hole itself, and that small amounts of upward convection of water may be occurring in the higher temperature areas of the Conasauga experiments.

  16. Proceedings of a workshop on the utilization of coal fuels in process heaters

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Almost 5% of the nation's energy consumption takes place in tubular process heaters. Currently, these units are gas- and, to a lesser extent, oil-fired. Process heaters provide energy for refining petroleum and the manufacture of numerous chemicals and petrochemicals. Since the current state-of-the-art, using waste heat recovery and forced draft burners, can achieve thermal efficiencies of about 90%, it is unlikely that current process heat and fuel requirements will be dramatically reduced by process modifications and/or conservation measures. Hence, if this sizeable, inexorable drain on our fluid petroleum reserves is to be halted, it seems reasonable to consider the utilization of coal and/or coal-based fuels to fire process heaters. In order to assess the feasibility and potential for a coal-based process heater industry, Brookhaven National Laboratory (BNL) organized a workshop to define and explore the various problems that must be solved in order to burn coal in process heaters. A primary aim of the workshop was to consider the design methodology for process heaters when firing coal and compare it to those for gas and oil firing. The overall conclusions were: that retrofitting present process heaters to coal fuel was impractical; that it would be difficult to fit larger heaters designed to burn coal into present refineries; that there would be difficulties with process heaters burning coal; and that a better approach would be one large utility coal heater with a circulating heat transfer medium. Seven papers have been entered individually into EDB and ERA. (LTN)

  17. Variation in outcomes in Veterans Affairs intensive care units with a computerized severity measure.

    Science.gov (United States)

    Render, Marta L; Kim, H Myra; Deddens, James; Sivaganesin, Siva; Welsh, Deborah E; Bickel, Karen; Freyberg, Ron; Timmons, Stephen; Johnston, Joseph; Connors, Alfred F; Wagner, Douglas; Hofer, Timothy P

    2005-05-01

    To quantify the variability in risk-adjusted mortality and length of stay of Veterans Affairs intensive care units using a computer-based severity of illness measure. Retrospective cohort study. A stratified random sample of 34 intensive care units in 17 Veterans Affairs hospitals. A consecutive sample of 29,377 first intensive care unit admissions from February 1996 through July 1997. Standardized mortality ratio (observed/expected deaths) and observed minus expected length of stay (OMELOS) with 95% confidence intervals were estimated for each unit using a hierarchical logistic (standardized mortality ratio) or linear (OMELOS) regression model with Markov Chain Monte Carlo simulation. We adjusted for patient characteristics including age, admission diagnosis, comorbid disease, physiology at admission (from laboratory data), and transfer status. Mortality across the intensive care units for the 12,088 surgical and 17,289 medical cases averaged 11% (range, 2-30%). Length of stay in the intensive care units averaged 4.0 days (range, mean unit length of stay 3.0-5.9). Standardized mortality ratio of the intensive care units varied from 0.62 to 1.27; the standardized mortality ratio and 95% confidence interval were units and >1.0 for seven intensive care units. OMELOS of the intensive care units ranged from -0.89 to 1.34 days. In a random slope hierarchical model, variation in standardized mortality ratio among intensive care units was similar across the range of severity, whereas variation in length of stay increased with severity. Standardized mortality ratio was not associated with OMELOS (Pearson's r = .13). We identified intensive care units whose indicators for mortality and length of stay differ substantially using a conservative statistical approach with a severity adjustment model based on data available in computerized clinical databases. Computerized risk adjustment employing routinely available data may facilitate research on the utility of intensive care

  18. Variation in strontium isotope ratios of archaeological fauna in the Midwestern United States: a preliminary study

    Science.gov (United States)

    Hedman, Kristin M.; Curry, B. Brandon; Johnson, Thomas M.; Fullagar, Paul D.; Emerson, Thomas E.

    2009-01-01

    Strontium isotope values (87Sr/86Sr) in bone and tooth enamel have been used increasingly to identify non-local individuals within prehistoric human populations worldwide. Archaeological research in the Midwestern United States has increasingly highlighted the role of population movement in affecting interregional cultural change. However, the comparatively low level of geologic variation in the Midwestern United States might suggest a corresponding low level of strontium variation, and calls into question the sensitivity of strontium isotopes to identify non-local individuals in this region. Using strontium isotopes of archaeological fauna, we explore the degree of variability in strontium ratios across this region. Our results demonstrate measurable variation in strontium ratios and indicate the potential of strontium analysis for addressing questions of origin and population movement in the Midwestern United States.

  19. Successful application of PIG decking technology for heat medium heater pipe in the PET unit%清管器清焦技术在聚酯装置热媒炉管上的成功应用

    Institute of Scientific and Technical Information of China (English)

    龚天寿; 杨文明

    2011-01-01

    清管器清焦技术具有清焦效果彻底、安全环保、工期短等特点。仪征化纤股份有限公司通过在聚酯热媒炉的成功试用,不但提高了热媒炉的热效率,而且使得该项技术向化纤行业迈出了成功的一步。%PIG decoking technology has advantages of thorough and effective decoking,safety and environmental protection,short duration and others.Yizheng Chemical Fibre Company Limited,SINOPEC has successful trial in polyester heat medium heater,it not only improves the thermal efficiency of heat medium heater,but also make this technology taken a successful step in the chemical fiber industry.

  20. 变频技术在300 MW机组低压加热器疏水泵上的应用%APPLICATION OF FREQUENCY-CONVERTING TECHNOLOGY ON DRAIN PUMP FOR LP HEATER OF A 300MW UNIT

    Institute of Scientific and Technical Information of China (English)

    陈强; 刘建华; 张乐群

    2001-01-01

    The drain system of LP heater was designed as a combined operation system of step-by-step gravity drain and drain pump. When the said pump is operating at constand speed, troublesome problems, shch as higher fault rate, larger pipeline vibration, shorter time for putting LP heater into operation etc, are ubiquitous. Using frequency-converting technology, the water level in LP heater can be controlled by converting the frequency of drain pump’s power supply instead of adjustment with valves. More than one year’s operation of the retrofitted system proved that the operation of said drain pump to be stable, safe and reliable .The rate of putting LP heater into operation reaches 100% and the effect of energy-saving is obvious. The said technology has been rapidly spread in use.%300 MW机组低压加热器疏水系统设计为逐级自流和低压加热器疏水泵联合运行方式,疏水泵定速运行时普遍存在泵故障率高、管道振动大、低压加热器投入率低等问题。利用变频技术将低压加热器水位控制方式由阀门调节改为疏水泵变频控制,改造后一年多运行表明疏水泵运行稳定,安全可靠,低压加热器投入率达100%,节能显著,并很快在湛江发电厂推广使用。

  1. Variation in voxel value distribution and effect of time between exposures in six CBCT units.

    Science.gov (United States)

    Spin-Neto, R; Gotfredsen, E; Wenzel, A

    2014-01-01

    The aim of this study is to assess the variation in voxel value distribution in volumetric data sets obtained by six cone beam CT (CBCT) units, and the effect of time between exposures. Six CBCT units [Cranex(®) 3D (CRAN; Soredex Oy, Tuusula, Finland), Scanora(®) 3D (SCAN; Soredex Oy), NewTom™ 5G (NEWT; QR Srl, Verona, Italy), Promax(®) Dimax 3 (Planmeca Oy, Helsinki, Finland), i-CAT (Imaging Sciences International, Hatfield, PA) and 3D Accuitomo FPD80 (Morita, Kyoto, Japan)] were tested. Two volumetric data sets of a dry human skull embedded in acrylic were acquired by each CBCT unit in two sessions on separate days. Each session consisted of 20 exposures: 10 acquired with 30 min between exposures and 10 acquired immediately one after the other. CBCT data were exported as digital imaging and communications in medicine (DICOM) files and converted to text files. The text files were re-organized to contain x-, y- and z-position and grey shade for each voxel. The files were merged to contain 1 record per voxel position, including the voxel values from the 20 exposures in a session. For each voxel, subtractions were performed between Data Set 1 and the remaining 19 data sets (1 - 2, 1 - 3, etc) in a session. Means, medians, ranges and standard deviations for grey shade variation in the subtraction data sets were calculated for each unit and session. For all CBCT units, variation in voxel values was observed throughout the 20 exposures. A "fingerprint" for the grey shade variation was observed for CRAN, SCAN and NEWT. For the other units, the variation was (apparently) randomly distributed. Large discrepancies in voxel value distribution are seen in CBCT images. This variation should be considered in studies that assess minute changes in CBCT images.

  2. Thermal response of transparent silver nanowire/PEDOT:PSS film heaters.

    Science.gov (United States)

    Ji, Shulin; He, Weiwei; Wang, Ke; Ran, Yunxia; Ye, Changhui

    2014-12-10

    Thermal response behavior of transparent silver nanowire/PEDOT:PSS film heaters are intensively studied for manipulating heating temperature, response time, and power consumption. Influences of substrate heat capacity, heat transfer coefficient between air and heater, sheet resistance and dimension of Ag nanowire film, on the thermal response are investigated from thermodynamic analysis. Suggestion is given for practical applications that if other parameters are fixed, Ag nanowire coverage can be utilized as an effective parameter to adjust the thermal response. The heat transfer coefficient plays opposite roles on thermal response speed and achievable steady temperature. A value of ≈32 W m(-2) K(-1) is obtained from transient process analysis after correcting it by considering heater resistance variation during heating tests. Guidance of designing heaters with a given response time is provided by forming Ag nanowire film with a suitable sheet resistance on substrate of appropriate material and a certain thickness. Thermal response tests of designed Ag heaters are performed to show higher heating temperature, shorter response time, and lower power consumption (179 °C cm(2) W(-1)) than ITO/FTO heaters, as well as homogeneous temperature distribution and stability for repeated use. Potential applications of the Ag heaters in window defogging, sensing and thermochromism are manifested.

  3. Parallel heater system for subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Christopher Kelvin (Houston, TX); Karanikas, John Michael (Houston, TX); Nguyen, Scott Vinh (Houston, TX)

    2011-10-25

    A heating system for a subsurface formation is disclosed. The system includes a plurality of substantially horizontally oriented or inclined heater sections located in a hydrocarbon containing layer in the formation. At least a portion of two of the heater sections are substantially parallel to each other. The ends of at least two of the heater sections in the layer are electrically coupled to a substantially horizontal, or inclined, electrical conductor oriented substantially perpendicular to the ends of the at least two heater sections.

  4. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norfolk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norfolk, CT (United States)

    2016-02-05

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publically available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(TM), A.O. Smith Voltex(R), and Stiebel Eltron Accelera(R) 300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  5. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Puttagunta, S.

    2013-08-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publicly available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(tm), A.O. Smith Voltex(r), and Stiebel Eltron Accelera(r)300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  6. SINGLE HEATER TEST FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    J.B. Cho

    1999-05-01

    The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M&O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied

  7. Fluid bed solids heater. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Preuit, L. C.

    1980-01-01

    A solids heater which operates at up to 2000 F was designed, fabricated, installed and operated through checkout at the Morgantown Energy Technology Center at Morgantown, West Virginia. The system, designated the 2000 F Fluid Bed Solids Heater (FBSH) uses a fluidized bed to heat limestone to 600 F and aluminium oxide or silicon carbide to 2000 F and discharges heated solids upon demand. The FBSH with added valve handling and pressurization equipment is known as the Valve Hot Solids Test Unit and is intended for use by the US Department of Energy for testing of valves for severe service applications in coal conversion and utilization processes. The FBSH as designed and supplied by Combustion Power Company includes process equipment, controls, the enclosing building and other associated equipment. In the 600 F range of operation it can circulate limestone through two valve test trains simultaneously on a continuous basis. Only one valve test train is used for 2000 F solids and operation in that range is also continuous. Limestone, crushed to minus 5/16 size, is heated, discharged, and recycled at a maximum average rate of 250 lb/min while aluminum oxide or silicon carbide, No. 8 grit, is circulated at rates up to 167 lb/min. The FBSH control system is designed for automatic operation, and capability is included for external computerized data acquisition and/or supervisory control. An operating and maintenance manual and as-built drawings have been submitted. This report describes the FBSH equipment, its design basis, and its operation. It has been prepared and submitted in fulfillment of Contract Number DIAC05-77ET10499.

  8. [Variations in the diagnostic confirmation process between breast cancer mass screening units].

    Science.gov (United States)

    Natal, Carmen; Fernández-Somoano, Ana; Torá-Rocamora, Isabel; Tardón, Adonina; Castells, Xavier

    2016-01-01

    To analyse variations in the diagnostic confirmation process between screening units, variations in the outcome of each episode and the relationship between the use of the different diagnostic confirmation tests and the lesion detection rate. Observational study of variability of the standardised use of diagnostic and lesion detection tests in 34 breast cancer mass screening units participating in early-detection programmes in three Spanish regions from 2002-2011. The diagnostic test variation ratio in percentiles 25-75 ranged from 1.68 (further appointments) to 3.39 (fine-needle aspiration). The variation ratio in detection rates of benign lesions, ductal carcinoma in situ and invasive cancer were 2.79, 1.99 and 1.36, respectively. A positive relationship between rates of testing and detection rates was found with fine-needle aspiration-benign lesions (R(2): 0.53), fine-needle aspiration-invasive carcinoma (R(2): 0 28), core biopsy-benign lesions (R(2): 0.64), core biopsy-ductal carcinoma in situ (R(2): 0.61) and core biopsy-invasive carcinoma (R(2): 0.48). Variation in the use of invasive tests between the breast cancer screening units participating in early-detection programmes was found to be significantly higher than variations in lesion detection. Units which conducted more fine-needle aspiration tests had higher benign lesion detection rates, while units that conducted more core biopsies detected more benign lesions and cancer. Copyright © 2016 SESPAS. Published by Elsevier Espana. All rights reserved.

  9. SELECTED ORGANIC POLLUTANT EMISSIONS FROM UNVENTED KEROSENE HEATERS

    Science.gov (United States)

    An exploratory study was performed to assess the semivolatile and nonvolatile organic pollutant emission rates from unvented kerosene space heaters. A well-tuned radiant heater and maltuned convective heater were tested for semivolatile and nonvolatile organic pollutant emiss...

  10. Design, Construction, and Qualification of a Microscale Heater Array for Use in Boiling Heat Transfer

    Science.gov (United States)

    Rule, T. D.; Kim, J.; Kalkur, T. S.

    1998-01-01

    Boiling heat transfer is an efficient means of heat transfer because a large amount of heat can be removed from a surface using a relatively small temperature difference between the surface and the bulk liquid. However, the mechanisms that govern boiling heat transfer are not well understood. Measurements of wall temperature and heat flux near the wall would add to the database of knowledge which is necessary to understand the mechanisms of nucleate boiling. A heater array has been developed which contains 96 heater elements within a 2.5 mm square area. The temperature of each heater element is held constant by an electronic control system similar to a hot-wire anemometer. The voltage that is being applied to each heater element can be measured and digitized using a high-speed A/D converter, and this digital information can be compiled into a series of heat-flux maps. Information for up to 10,000 heat flux maps can be obtained each second. The heater control system, the A/D system and the heater array construction are described in detail. Results are presented which show that this is an effective method of measuring the local heat flux during nucleate and transition boiling. Heat flux maps are obtained for pool boiling in FC-72 on a horizontal surface. Local heat flux variations are shown to be three to six times larger than variations in the spatially averaged heat flux.

  11. Oscillations in the power spectra of motor unit signals caused by refractoriness variations

    Science.gov (United States)

    Hu, X. L.; Tong, K. Y.; Hung, L. K.

    2004-09-01

    The refractory period of a motor unit is an important mechanism that regulates the motor unit firing, and its variation has been found in many physiological cases. In this study, a new observation that an increase in the motor unit refractoriness results in an enhancement of oscillations, or ripple effects, in the motor unit output power density spectra (PDS) has been identified and studied. The effects of the refractoriness variation on the PDS of motor unit firing were investigated on three levels: theoretical modeling, simulation and electromyographic (EMG) experimentation on human subjects. Both theoretical modeling and simulation showed the enhanced oscillations, ripple effects, in MUAPT PDS, given the increase in the refractoriness. It was also found that the extent of the increment in output PDS oscillation could be related to the motor unit size and the mean firing rate of the stimulation. A needle EMG experiment on biceps brachii muscles of five healthy human subjects was carried out during isometric contraction at 20% maximum voluntary contraction (MVC) for 20 s with a fatigue effort proceeded by MVC. The increased oscillations in the PDS of the real MUAPTs were observed with the rising of the motor unit refractoriness due to fatigue. The study gives new information for EMG spectra interpretation, and also provides a potential method for accessing neuromuscular transmission failure (NTF) due to fatigue during voluntary contraction.

  12. Strategy Guideline. Proper Water Heater Selection

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2015-04-09

    This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

  13. Strategy Guideline: Proper Water Heater Selection

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation, Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation, Davis, CA (United States); German, A. [Alliance for Residential Building Innovation, Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation, Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-04-01

    This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

  14. 49 CFR 393.77 - Heaters.

    Science.gov (United States)

    2010-10-01

    ... all hot water and steam heater systems shall be specifically designed and constructed for that purpose... when used for heating the cargo of tank motor vehicles. (3) Heaters permitting fuel leakage. Any type... air, heated or to be heated, from the engine compartment or from direct contact with any portion...

  15. "Starfish" Heater Head For Stirling Engine

    Science.gov (United States)

    Vitale, N.

    1993-01-01

    Proposed "starfish" heater head for Stirling engine enables safe use of liquid sodium as heat-transfer fluid. Sodium makes direct contact with heater head but does not come in contact with any structural welds. Design concept minimizes number of, and simplifies nonstructural thermal welds and facilitates inspection of such welds.

  16. Solar Water-Heater Design Package

    Science.gov (United States)

    1982-01-01

    Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.

  17. Subsurface connection methods for subsurface heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Bass, Ronald Marshall (Houston, TX); Kim, Dong Sub (Sugar Land, TX); Mason, Stanley Leroy (Allen, TX); Stegemeier, George Leo (Houston, TX); Keltner, Thomas Joseph (Spring, TX); Carl, Jr., Frederick Gordon (Houston, TX)

    2010-12-28

    A system for heating a subsurface formation is described. The system includes a first elongated heater in a first opening in the formation. The first elongated heater includes an exposed metal section in a portion of the first opening. The portion is below a layer of the formation to be heated. The exposed metal section is exposed to the formation. A second elongated heater is in a second opening in the formation. The second opening connects to the first opening at or near the portion of the first opening below the layer to be heated. At least a portion of an exposed metal section of the second elongated heater is electrically coupled to at least a portion of the exposed metal section of the first elongated heater in the portion of the first opening below the layer to be heated.

  18. Effects of heated seat and foot heater on thermal comfort and heater energy consumption in vehicle.

    Science.gov (United States)

    Oi, Hajime; Yanagi, Kotaro; Tabata, Koji; Tochihara, Yutaka

    2011-08-01

    Subjective experiments involving 12 different conditions were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal sensation and thermal comfort. The experimental conditions involved various combinations of the operative temperature in the test room (10 or 20°C), a heated seat (on/off) and a foot heater (room operative temperature +10 or +20°C). The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. The room operative temperature at which the occupants felt a 'neutral' overall thermal sensation was decreased by about 3°C by using the heated seat or foot heater and by about 6°C when both devices were used. Moreover, the effects of these devices on vehicle heater energy consumption were investigated using simulations. As a result, it was revealed that heated seats and foot heaters can reduce the total heater energy consumption of vehicles. Statement of Relevance: Subjective experiments were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal comfort. The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. These devices can reduce the total heater energy consumption in vehicles.

  19. Biogas Digester with Simple Solar Heater

    OpenAIRE

    Kh S Karimov; Muhammad Abid

    2012-01-01

    ABSTRACT: In this research work, the design, fabrication and investigation of a biogas digester with simple solar heater are presented. For the solar heater, a built-in reverse absorber type heater was used. The maximum temperature (50°C) inside the methane tank was taken as a main parameter for the design of the digester. Then, the energy balance equation for the case of a static mass of fluid being heated was used to model the process. The parameters of thermal insulation of the methane tan...

  20. Particulate matter sensor with a heater

    Science.gov (United States)

    Hall, Matthew

    2011-08-16

    An apparatus to detect particulate matter. The apparatus includes a sensor electrode, a shroud, and a heater. The electrode measures a chemical composition within an exhaust stream. The shroud surrounds at least a portion of the sensor electrode, exclusive of a distal end of the sensor electrode exposed to the exhaust stream. The shroud defines an air gap between the sensor electrode and the shroud and an opening toward the distal end of the sensor electrode. The heater is mounted relative to the sensor electrode. The heater burns off particulate matter in the air gap between the sensor electrode and the shroud.

  1. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, E. Weitzel, C. Backman

    2017-06-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements.

  2. Study on Oxygenated Treatment of High-pressure Heater Steam-Liquid Phase Transition Zone for Ultra-Supercritical Units%高压加热器汽液相变区氧化处理技术在超超临界发电机组上的应用

    Institute of Scientific and Technical Information of China (English)

    施国忠; 刘春红

    2015-01-01

    The traditional oxygenated treatment of feedwater jeopardizes operation safety of units due to falling-off of oxide skin of superheater. However, low oxygenated treatment of feedwater can not drastically e-liminate flow accelerated corrosion of feedwater and steam-liquid phase transition zone. After oxygenated treat-ment in steam-liquid phase transition zone of high-pressure heater of ultra-supercritical units, accurate, fixed-point and quantitative oxygenated treatment is achieved and flow accelerated corrosion of phase transition zone for high-pressure heater is successfully eliminated; in the meantime, the risk of oxide skin falling-off of superheater is prevented and the security and economical efficiency of the units are improved. After oxygenat-ed treatment of steam-liquid phase transition zone, conversion speed of the dense Fe2O3 oxide film is fast, Fe concentration of high-pressure heater drainage decreases by 85%and Fe concentration is less than 1μg/L.%传统的给水加氧工艺由于存在过热器氧化皮剥落风险,危及机组安全运行,而给水低氧处理工艺又无法彻底解决给水和汽液相变区流动加速腐蚀的问题。对超超临界发电机组高压加热器汽液相变区采用氧化处理技术,实现精确、定点、定量加氧处理,成功解决了高压加热器汽液相变区的流动加速腐蚀问题,又避免了过热器氧化皮剥落的风险,提高了机组的安全经济性。高加汽液相变区进行氧化处理后,致密的Fe2O3氧化膜转化速度快,高加疏水Fe浓度下降达85%, Fe浓度小于1μg/L。

  3. 46 CFR 52.25-15 - Fired thermal fluid heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Fired thermal fluid heaters. 52.25-15 Section 52.25-15... Boiler Types § 52.25-15 Fired thermal fluid heaters. (a) Fired thermal fluid heaters shall be designed...) Each fired thermal fluid heater must be fitted with a control which prevents the heat transfer...

  4. 46 CFR 63.25-5 - Fired thermal fluid heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Fired thermal fluid heaters. 63.25-5 Section 63.25-5... heaters. (a) Construction. Fired thermal fluid heaters must meet the requirements of part 52 of this chapter, as applicable. (b) Controls. Fired thermal fluid heaters must have a low fluid level...

  5. Varying properties along lengths of temperature limited heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Xie, Xueying (Houston, TX); Miller, David Scott (Katy, TX); Ginestra, Jean Charles (Richmond, TX)

    2011-07-26

    A system for heating a subsurface formation is described. The system includes an elongated heater in an opening in the formation. The elongated heater includes two or more portions along the length of the heater that have different power outputs. At least one portion of the elongated heater includes at least one temperature limited portion with at least one selected temperature at which the portion provides a reduced heat output. The heater is configured to provide heat to the formation with the different power outputs. The heater is configured so that the heater heats one or more portions of the formation at one or more selected heating rates.

  6. Experimental studies of operating characteristics of a downhole electric heater

    Energy Technology Data Exchange (ETDEWEB)

    Simkin, E.M.; Sergeev, A.I.; Sheinman, A.B.

    1967-06-01

    A new type of electric downhole heater for deparaffinization and heating of formations in oil wells is described. The heater is a hollow hermetic cylinder, which contains an electrode insulated from the body of the heater. The cylinder contains a predetemined volume of water of fixed electrical resistance. Resistance of this water is adjusted by addition of salt. A cable supplying the electrode with electric current also ground the heater by body. The current passes through the water, heats it, and produces steam. The steam heats up the hermetically sealed body of the heater, and heat flows to the well fluid around the heater. A schematic diagram of the heater is shown. Thermal output of the heater depends on current supplied, dimension of heater and components, resistance and volume of water in heater, and other parameters. All these factors are correlated with heat output by a series of graphs and equations.

  7. Slat Heater Boxes for Thermal Vacuum Testing

    Science.gov (United States)

    Ungar, Eugene

    2003-01-01

    Slat heater boxes have been invented for controlling the sink temperatures of objects under test in a thermal vacuum chamber, the walls of which are cooled to the temperature of liquid nitrogen. A slat heater box (see Figure 1) includes a framework of struts that support electrically heated slats that are coated with a high-emissivity optically gray paint. The slats can be grouped together into heater zones for the purpose of maintaining an even temperature within each side. The sink temperature of an object under test is defined as the steady-state temperature of the object in the vacuum/ radiative environment during the absence of any internal heat source or sink. The slat heater box makes it possible to closely control the radiation environment to obtain a desired sink temperature. The slat heater box is placed inside the cold thermal vacuum chamber, and the object under test is placed inside (but not in contact with) the slat heater box. The slat heaters occupy about a third of the field of view from any point on the surface of the object under test, the remainder of the field of view being occupied by the cold chamber wall. Thus, the radiation environment is established by the combined effects of the slat heater box and the cold chamber wall. Given (1) the temperature of the chamber wall, (2) the fractions of the field of view occupied by the chamber wall and the slat heater box, and (3) the emissivities of the slats, chamber wall, and the surface of object under test, the slat temperature required to maintain a desired sink temperature can be calculated by solving the equations of gray-body radiation for the steady-state adiabatic case (equal absorption and emission by the object under test). Slat heater boxes offer an important advantage over the infrared lamps that have been previously used to obtain desired sink temperatures: In comparison with an infrared lamp, a slat heater box provides a greater degree of sink temperature uniformity for a test

  8. Diesel particulate filter with zoned resistive heater

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-03-08

    A diesel particulate filter assembly comprises a diesel particulate filter (DPF) and a heater assembly. The DPF filters a particulate from exhaust produced by an engine. The heater assembly has a first metallic layer that is applied to the DPF, a resistive layer that is applied to the first metallic layer, and a second metallic layer that is applied to the resistive layer. The second metallic layer is etched to form a plurality of zones.

  9. Note: Improved wire-wound heater.

    Science.gov (United States)

    Steinmann, Ricardo G; Vitoux, Hugo

    2015-01-01

    The authors have measured, at cryogenic temperature, the upper limit of the heat transfer in different configurations of a wire-wound heater. We found that the heat transferred has an upper limit of about 15 W/cm(2) and is dependent on the diameter of the wire. In this paper, we present three ways of increasing the heat transferred by this type of heater and its application in different continuous flow cryostats.

  10. Note: Improved wire-wound heater

    Science.gov (United States)

    Steinmann, Ricardo G.; Vitoux, Hugo

    2015-01-01

    The authors have measured, at cryogenic temperature, the upper limit of the heat transfer in different configurations of a wire-wound heater. We found that the heat transferred has an upper limit of about 15 W/cm2 and is dependent on the diameter of the wire. In this paper, we present three ways of increasing the heat transferred by this type of heater and its application in different continuous flow cryostats.

  11. Variation in Surgical Antibiotic Prophylaxis for Outpatient Pediatric Urological Procedures at United States Children's Hospitals.

    Science.gov (United States)

    Chan, Katherine H; Bell, Teresa; Cain, Mark; Carroll, Aaron; Benneyworth, Brian D

    2017-03-01

    Guidelines recommend surgical antibiotic prophylaxis for clean-contaminated procedures but none for clean procedures. The purpose of this study was to describe variations in surgical antibiotic prophylaxis for outpatient urological procedures at United States children's hospitals. Using the PHIS (Pediatric Health Information System®) database we performed a retrospective cohort study of patients younger than 18 years who underwent clean and/or clean-contaminated outpatient urological procedures from 2012 to 2014. We excluded those with concurrent nonurological procedures or an abscess/infected wound. We compared perioperative antibiotic charges for clean vs clean-contaminated procedures using a multilevel logistic regression model with a random effect for hospital. We also examined whether hospitals that were guideline compliant for clean procedures, defined as no surgical antibiotic prophylaxis, were also compliant for clean-contaminated procedures using the Pearson correlation coefficient. We examined hospital level variation in antibiotic rates using the coefficient of variation. A total of 131,256 patients with a median age of 34 months at 39 hospitals met study inclusion criteria. Patients undergoing clean procedures were 14% less likely to receive guideline compliant surgical antibiotic prophylaxis than patients undergoing clean-contaminated procedures (OR 0.86, 95% CI 0.84-0.88, p variation was seen for hospital level compliance with surgical antibiotic prophylaxis for clean-contaminated procedures (range 9.8% to 97.8%, coefficient of variation 0.36) than for clean procedures (range 35.0% to 98.2%, coefficient of variation 0.20). Hospitals that used surgical antibiotic prophylaxis appropriately for clean-contaminated procedures were likely to use surgical antibiotic prophylaxis inappropriately for clean procedures. More variation was seen in hospital level guideline compliance for clean-contaminated procedures. Copyright © 2017 American Urological

  12. Intelligent annunciator for solar water heater

    Science.gov (United States)

    Chen, Xiao

    2009-07-01

    The solar water heater has advantages of low cost, no pollution, safety, energy conservation and is very suitable for users in rural area. But many now used solar water heater has no alarm device resulting water and resource wasting because of forgetting to turn off the valve after water sailing upstream. To overcome this defect, an intelligent annunciator for solar water heater installed at the end of the return pipe is presented and designed in order to remind the user. Firstly, the advantages and disadvantages of automatic and manual sailing upstream are compared concluding that manual sailing upstream is more trustiness. Then an annunciator for solar water heater is studied and ameliorated. Its principle, parameters index and functions are introduced. The annunciator uses CD4069 chip as the core circuit with very little assistant circuit. It can provide sound and light alarm at the same time. This annunciator for solar water heater water is very simple in production, low cost, the use of safe and convenient. The annunciator is applicable to all solar power products, including various types of early installation of solar power water heaters and water tanks without changing their structures. It can meet family and industrial environmental applications.

  13. Progress in CO2 Capture Using Amino Acid Ionic Liquid Analysis of Effects of High Pressure Heater Rejection on 300 MW Unit%高加解列对300 MW循环流化床机组的影响分析

    Institute of Scientific and Technical Information of China (English)

    苗俊明; 宋晓童; 徐钢

    2014-01-01

    Because the exhaust gas temperature on the high level for a long time threatens the safe operation of the bag filter, a power plant relies on the removal of some high pressure ( HP) regenerative heater sunder high load in the summer to reduce the exhaust temperature. In order to assess the influence of removing the HP regeneration heaters on thermal performance, and give a guideline, in this paper, the HP heater off-line was tested, the solution was then calculated using boiler/turbine operating data. The result shows that the temperature of feedwater decrea-ses rapidly after removing the HP heater, the temperature of exhaust decreases and the safety of bag filter is im-proved. Every HP regenerative heater removing can get the water temperature decrease 30~40 ℃, while the ex-haust temperature decreases 10~15 ℃. From an economic perspective, although the boiler thermal efficiency in-creases, the overall economy declines dramatically and the rate of coal consumption increases 2~8 g/kW·h due to the lower thermal efficiency of the unit, the operation costs increase nearly 340~1 000 thousand yuan per year.%因为排烟温度偏高,威胁布袋除尘器的安全,某热电厂在大规模技改之前,夏季高负荷工况下只能切除一级或多级高压回热加热器来降低烟气温度。为了研究切除高加对机组热力性能的影响规律并给出指导建议,首先开展了实际运行机组的高加投退实验,然后利用锅炉/汽轮机运行数据对运行工况下退出高加的方案进行了理论计算与分析,结果表明:退出高加后,给水温度迅速降低,排烟温度随之降低,保护了除尘器安全;每退出一级高加,给水出口温度降低约30~40益,排烟温度则降低10~15益;然而从机组的经济性角度看,虽然退出高加后锅炉热效率略有上升,然而机组总体热效率大幅下降,供电煤耗上升2~8 g/kW·h,按年切除高加运行1000 h估算,年燃料费用将上升34~100万元。

  14. Geographic Variation in Hip Fracture Among United States Long-Stay Nursing Home Residents

    Science.gov (United States)

    Banerjee, Geetanjoli; Zullo, Andrew R.; Berry, Sarah D.; Lee, Yoojin; McConeghy, Kevin; Kiel, Doug P.; Mor, Vincent

    2016-01-01

    Introduction Despite high rates of hip fracture among United States (US) nursing home (NH) residents, little is known about geographic variation in hip fracture incidence. We used nationally representative data to identify geographic variation in hip fracture among US NH residents. Design and setting Retrospective cohort study using Part A claims for a 100% of Medicare enrollees in 15,289 NHs linked to NH minimum data set and Online Survey, Certification, and Reporting databases. Participants A total of 891,085 long-stay (continuous residence of ≥100 days) NH residents ≥65 years old. Measurements Medicare Part A claims documenting a hip fracture. Mean incidence rates of hip fracture for long-stay NH residents were calculated for each state and US Census Division from 2007 to 2010. Results The age-, sex-, and race-adjusted incidence rate of hip fracture ranged from 1.49 hip fractures/100 person-years (Hawaii) to 3.60 hip fractures/100 person-years (New Mexico), with a mean of 2.38 (standard deviation 0.43) hip fractures/100 person-years. The mean incidence of hip fracture was 1.7-fold greater in the highest quintile than the lowest. Conclusions We observed modest US state and regional variation in hip fracture incidence among long-stay NH residents. Future studies should assess whether state policies or NH characteristics explain the variation. PMID:27461867

  15. Regional variation of climatic influences on West Nile virus outbreaks in the United States.

    Science.gov (United States)

    Wimberly, Michael C; Lamsal, Aashis; Giacomo, Paolla; Chuang, Ting-Wu

    2014-10-01

    The national resurgence of human West Nile virus (WNV) disease in 2012 raised questions about the factors responsible for WNV outbreaks. Interannual climatic variations may influence WNV amplification and transmission to humans through multiple pathways, including mosquito breeding habitats, gonotrophic cycles, extrinsic incubation, avian communities, and human behavior. We examined the influences of temperature and precipitation anomalies on interannual variation in human WNV cases in three regions of the United States. There were consistent positive influences of winter temperatures, weaker and more variable positive effects of spring and summer temperatures, and highly variable precipitation effects that ranged from positive to negative. The overwintering period may be a particularly important climatic constraint on the dynamics of WNV in cold-temperate regions of North America. Geographic differences in the seasonal timing and relative importance of climatic drivers of WNV risk likely reflect underlying variability in key ecological and social characteristics.

  16. High Efficiency R-744 Commercial Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Elbel, Dr. Stefan W.; Petersen, Michael

    2013-04-25

    The project investigated the development and improvement process of a R744 (CO2) commercial heat pump water heater (HPWH) package of approximately 35 kW. The improvement process covered all main components of the system. More specific the heat exchangers (Internal heat exchanger, Evaporator, Gas cooler) as well as the expansion device and the compressor were investigated. In addition, a comparison to a commercially available baseline R134a unit of the same capacity and footprint was made in order to compare performance as well as package size reduction potential.

  17. Total variation regularization of geodetically and geologically constrained block models for the Western United States

    Science.gov (United States)

    Evans, Eileen L.; Loveless, John P.; Meade, Brendan J.

    2015-08-01

    Geodetic observations of interseismic deformation in the Western United States provide constraints on microplate rotations, earthquake cycle processes, and slip partitioning across the Pacific-North America Plate boundary. These measurements may be interpreted using block models, in which the upper crust is divided into microplates bounded by faults that accumulate strain in a first-order approximation of earthquake cycle processes. The number and geometry of microplates are typically defined with boundaries representing a limited subset of the large number of potentially seismogenic faults. An alternative approach is to include a large number of potentially active faults bounding a dense array of microplates, and then algorithmically estimate the boundaries at which strain is localized. This approach is possible through the application of a total variation regularization (TVR) optimization algorithm, which simultaneously minimizes the L2 norm of data residuals and the L1 norm of the variation in the differential block motions. Applied to 3-D spherical block models, the TVR algorithm can be used to reduce the total variation between estimated rotation vectors, effectively grouping microplates that rotate together as larger blocks, and localizing fault slip on the boundaries of these larger block clusters. Here we develop a block model comprised of 137 microplates derived from published fault maps, and apply the TVR algorithm to identify the kinematically most important faults in the western United States. This approach reveals that of the 137 microplates considered, only 30 unique blocks are required to approximate deformation in the western United States at a residual level of <2 mm yr-1.

  18. Fuzzy Probability Signed Directed Graph Unit Model and Fault Diagnosis of High Pressure Heater System in Thermal Power Plant%模糊概率符号有向图单元模型及电站高加系统故障诊断

    Institute of Scientific and Technical Information of China (English)

    邱凤翔; 郭振宇; 徐治皋; 司风琪

    2011-01-01

    针对复杂系统的符号有向图((signed directed graph,SDG)模型结构复杂,搜索路径"组合爆炸"等缺点,将SDG符号识别能力和知识库易于维护的特点相结合,提出了模糊概率SDG单元模型,建立了模糊概率SDG单元库,并描述了基于SDG单元库的故障推理方法.复杂系统的测点不完备性和参数耦合性是故障诊断中亟需解决的问题,在建立SDG单元库时,充分考虑了这两个问题.以某,600MW机组高加系统为例,采取仿真与现场经验相结合建立SDG单元库,并通过现场故障实例验证了该故障推理方法的有效性.SDG单元模型结构简单,推理快速,有效避免了"组合爆炸"的问题,故障诊断准确率高,能有效克服现场测点缺失和系统参数耦合问题.%The structure of signed directed graph (SDG) of complex system is complexity, and fault diagnosis reasoning of SDG will lead to combination explosion problem of search path. Fuzzy probabilistic SDG unit model was proposed and fuzzy probabilistic SDG unit library was built with the signed recognition capability of SDG combined with knowledge base.And the fault diagnosis reasoning method was described. The incomplete information of measuring points and the coupling of system were two problems of fault diagnosis and these two problems were considered fully on the process of SDG modeling. A comprehensive and reliable SDG unit library was built for fault diagnosis reasoning of high pressure heater system of a 600MW unit, which was obtained by combination of simulation and field experience. And this method was valid by field fault of high pressure heater system. The structure of SDG unit model is simple and the speed of diagnosis reasoning is fast. The result shows that this method can avoid the combination explosion problem and solve the lack of measuring points and the coupling of system.

  19. Heat Pump Water Heater Durabliltiy Testing - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAND.

    2004-05-29

    Ten heat pump water heaters (HPWH) were placed in an environmentally controlled test facility and run through a durability test program of approximately 7300 duty cycles (actual cycles accumulated ranged from 6640 to 8324 for the ten units). Five of the units were upgraded integral types (HPWH mounted on storage tank, no pump) from the same manufacturer as those tested in our first durability program in 2001 (Baxter and Linkous, 2002). The other five were ''add-on'' type units (HPWH with circulation pump plumbed to a separate storage tank) from another manufacturer. This durability test was designed to represent approximately 7-10 years of normal operation to meet the hot water needs of a residence. The integral units operated without incident apart from two control board failures. Both of these were caused by inadvertent exposure to very hot and humid (>135 F dry bulb and >120 F dew point) conditions that occurred due to a test loop failure. It is not likely that any residential water heater would be installed where such conditions were expected so these failures are not considered a long-term reliability concern. Two of the integral HPWHs featured a condensate management system (CMS) option that effectively eliminated any need for an evaporator condensate drain, but imposed significant efficiency penalties when operating in high humidity ambient conditions. The add-on units experienced no operational failures (breakdowns with loss of hot water production) during the course of the testing. However, their control systems exhibited some performance degradation under the high temperature, high humidity test conditions--HPWHs would shut off with tank water temperatures 15-20 F lower than when operating under moderate ambient conditions. One unit developed a refrigerant leak during the test program and lost about 50% of its charge resulting in reduced efficiency. Efficiency measurements on all the integral units and four of the add-on units showed

  20. Single-structure heater and temperature sensor using a p-type polycrystalline diamond resistor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, G.S.; Aslam, D.M. [Michigan State Univ., East Lansing, MI (United States). Dept. of Electrical Engineering

    1996-05-01

    Heat generation and temperature sensing are required for heating applications and for liquid level sensors, mass flow meters, and vacuum and pressure gauges which are based on variations of heat dissipation. Heat generation and temperature sensing are reported in a single p-type diamond resistor fabricated on an oxidized Si substrate using diamond film technology compatible with integrated circuit (IC) processing. Power densities in excess of 600 W/in.{sup 2} are observed for the heaters. The temperature response of the sensor is characterized in the temperature range of 300--725 K. Such a diamond heater/sensor device is reported for the first time.

  1. Performance characterization of a hydrogen catalytic heater.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry Alan; Kanouff, Michael P.

    2010-04-01

    This report describes the performance of a high efficiency, compact heater that uses the catalytic oxidation of hydrogen to provide heat to the GM Hydrogen Storage Demonstration System. The heater was designed to transfer up to 30 kW of heat from the catalytic reaction to a circulating heat transfer fluid. The fluid then transfers the heat to one or more of the four hydrogen storage modules that make up the Demonstration System to drive off the chemically bound hydrogen. The heater consists of three main parts: (1) the reactor, (2) the gas heat recuperator, and (3) oil and gas flow distribution manifolds. The reactor and recuperator are integrated, compact, finned-plate heat exchangers to maximize heat transfer efficiency and minimize mass and volume. Detailed, three-dimensional, multi-physics computational models were used to design and optimize the system. At full power the heater was able to catalytically combust a 10% hydrogen/air mixture flowing at over 80 cubic feet per minute and transfer 30 kW of heat to a 30 gallon per minute flow of oil over a temperature range from 100 C to 220 C. The total efficiency of the catalytic heater, defined as the heat transferred to the oil divided by the inlet hydrogen chemical energy, was characterized and methods for improvement were investigated.

  2. Dielectric Heaters for Testing Spacecraft Nuclear Reactors

    Science.gov (United States)

    Sims, William Herbert; Bitteker, Leo; Godfroy, Thomas

    2006-01-01

    A document proposes the development of radio-frequency-(RF)-driven dielectric heaters for non-nuclear thermal testing of the cores of nuclear-fission reactors for spacecraft. Like the electrical-resistance heaters used heretofore for such testing, the dielectric heaters would be inserted in the reactors in place of nuclear fuel rods. A typical heater according to the proposal would consist of a rod of lossy dielectric material sized and shaped like a fuel rod and containing an electrically conductive rod along its center line. Exploiting the dielectric loss mechanism that is usually considered a nuisance in other applications, an RF signal, typically at a frequency .50 MHz and an amplitude between 2 and 5 kV, would be applied to the central conductor to heat the dielectric material. The main advantage of the proposal is that the wiring needed for the RF dielectric heating would be simpler and easier to fabricate than is the wiring needed for resistance heating. In some applications, it might be possible to eliminate all heater wiring and, instead, beam the RF heating power into the dielectric rods from external antennas.

  3. Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

    Energy Technology Data Exchange (ETDEWEB)

    Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

    1980-01-01

    Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

  4. Combustion-Driven Oscillation in Process Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Seebold, J.G. [Chevron Corporation (Retired), 198 James Avenue, Atherton, CA 94027 (United States)

    2005-10-15

    At this moment in thousands of process heaters all over the world there are, to borrow a phrase from the late Carl Sagan, 'billions and billions' of Btu/hr beneficially being released entirely free of pulsation. On those few occasions, perhaps a dozen and a half in my career, when I would get the inevitable 'Why me?' call, I have generally responsed with something like, 'Consider yourself lucky, you have a rare scientific curiosity on your hands'. Reflecting on the solutions ultimately found, I'm reminded that many years ago my friend Abbott Putnam shared with me an early AGA (American Gas Association) field-service bulletin that included a prescription for eliminating combustion-driven oscillations in home heating units; viz., 'Drill a hole; if that doesn't work, drill another hole' or words to that effect. Many times have I wished that I still had a copy of that bulletin and in this paper we will have occasion, once again, to reflect upon the value of that advice. In this paper we will discuss an instance that arose in a pioneering installation of a breakthrough development of 'extremely', to distinguish it from 'ultra', low-NOx lean premix burner technology. We will illustrate how, when and under what circumstances combustion-driven oscillation can arise; we will touch on the many alternatives for its elimination that were considered and investigated; and we will discuss three practical alternatives for eliminating combustion-driven oscillations.

  5. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation; Weitzel, E. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation

    2017-03-03

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  6. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-11-22

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  7. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  8. Primary helium heater for propellant pressurization systems

    Science.gov (United States)

    Reichmuth, D. M.; Nguyen, T. V.; Pieper, J. L.

    1991-01-01

    The primary helium heater is a unique design that provides direct heating of pressurant gas for large pressure fed propulsion systems. It has been conceptually designed to supply a heated (800-1000 R) pressurization gas to both a liquid oxygen and an RP-1 propellant tank. This pressurization gas is generated within the heater by mixing super critical helium (40-300 R and 3000-1600 psi) with an appropriate amount of combustion products from a 4:1 throttling stoichiometric LO2/LH2 combustor. This simple, low cost and reliable mixer utilizes the large quantity of helium to provide stoichiometric combustor cooling, extend the throttling limits and enhance the combustion stability margin. Preliminary combustion, thermal, and CFD analyses confirm that this low-pressure-drop direct helium heater can provide the constant-temperature pressurant suitable for tank pressurization of both fuel and oxidizer tanks of large pressure fed vehicles.

  9. Economic analysis of residential solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-23

    A typical residential solar water heater, and typical cost and performance information are described briefly. The monthly costs and savings of the typical system are discussed. Economic evaluations of solar water heaters are presented in increasingly complex levels of detail. Utilizing a typical system, the effective interest rate that the purchaser of a system would receive on money invested is shown for all regions of the country. The importance of numerous variables that can make a significant difference on the economics of the system is described. Methods for calculating the Payback Period for any non-typical solar water heater are described. This calculated Payback Period is then shown to be related to the effective interest rate that the puchaser of the system would receive for a typical set of economic conditions. A method is presented to calculate the effective interest rate that the solar system would provide. (MHR)

  10. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-19

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  11. One-year assessment of a solar space/water heater--Clinton, Mississippi

    Science.gov (United States)

    1981-01-01

    Unit called "System 4" integrated into space-heating and hot-water systems of dormitory satisfied 32 percent of building heat load. System 4 includes flat-plate air collectors, circulation blowers, rock storage bed with heat exchanger, two hot water tanks, and auxiliary heaters. Report describes performance of system and subsystems, operating-energy requirements and savings, and performance parameters.

  12. Increasing reliability of system water heaters for steam-turbine installations at the design stage

    Science.gov (United States)

    Brezgin, V. I.; Brodov, Yu. M.; Brezgin, D. V.

    2015-12-01

    A system for designing water heaters of steam-turbine installations based on uniting standards, reference information, and some numerical procedures with design procedures via wide use of parameterization is considered. The developed design system is based on extensive application of modern information technologies.

  13. Carbazole based electrochromic polymers with benzoazole units: Effect of heteroatom variation on electrochromic performance

    Directory of Open Access Journals (Sweden)

    C. Doyranli

    2016-09-01

    Full Text Available A series of carbazole-based polymers were synthesized via Suzuki polymerization between N-(2-ethylhexylcarbazole-3,6-bis(ethyleneboronate (Cbz and dibromobenzazole unit. Three different polymers, PCBN, PCBS and PCBSe were obtained from 4,7-dibromo-2-hexyl-2H-benzotriazole (BN, 4,7-dibromo-2,1,3-benzothiadiazole- (BS and 4,7-dibromo-2,1,3-benzoselenadiazole (BSe, respectively. It is observed that, the variation of heteroatoms (N,S and Se on the benzazole unit have most important effect on electro-optic properties of the PCBX polymers. Neutral state color of the polymer films and their electrochromic performances are also influenced. Among the synthesized polymers, the PCBS bearing 2,1,3-benzothiadiazole as acceptor units has a broad absorption and 50% of ΔT in the near-IR regime at the oxidized state. This property of PCBS is a great advantage for near-IR electrochromic applications.

  14. Genetic variation of wheat streak mosaic virus in the United States Pacific Northwest.

    Science.gov (United States)

    Robinson, Megan D; Murray, Timothy D

    2013-01-01

    Wheat streak mosaic virus (WSMV), the cause of wheat streak mosaic, is a widespread and damaging pathogen of wheat. WSMV is not a chronic problem of annual wheat in the United States Pacific Northwest but could negatively affect the establishment of perennial wheat, which is being developed as an alternative to annual wheat to prevent soil erosion. Fifty local isolates of WSMV were collected from 2008 to 2010 near Lewiston, ID, Pullman, WA, and the United States Department of Agriculture Central Ferry Research Station, near Pomeroy, WA to determine the amount of genetic variation present in the region. The coat protein gene from each isolate was sequenced and the data subjected to four different methods of phylogenetic analyses. Two well-supported clades of WSMV were identified. Isolates in clade I share sequence similarity with isolates from Central Europe; this is the first report of isolates from Central Europe being reported in the United States. Isolates in clade II are similar to isolates originating from Australia, Argentina, and the American Pacific Northwest. Nine isolates showed evidence of recombination and the same two well-supported clades were observed when recombinant isolates were omitted from the analysis. More polymorphic sites, parsimony informative sites, and increased diversity were observed in clade II than clade I, suggesting more recent establishment of the virus in the latter. The observed diversity within both clades could make breeding for durable disease resistance in perennial wheat difficult if there is a differential response of WSMV resistance genes to isolates from different clades.

  15. Variation in Care for Patients with Irritable Bowel Syndrome in the United States.

    Directory of Open Access Journals (Sweden)

    Brian E Lacy

    Full Text Available Irritable bowel syndrome (IBS affects nearly one in seven Americans. Significant national variations in care may exist, due to a current lack of standardized diagnosis and treatment algorithms; this can translate into a substantial additional economic burden. The study examines healthcare resource utilization in patients with IBS and in the subset of IBS patients with constipation (IBS-C and analyzes the variation of IBS care for these patients across the United States (US.Healthcare resource use (HRU, including gastrointestinal (GI procedures and tests, all-cause and intestinal-related medical visits, GI specialist visits, and constipation or diarrhea pharmacy prescriptions for IBS patients enrolled in a large US administrative claims database (2001-2012 were analyzed for the 24-month period surrounding first diagnosis. Multivariate regression models, adjusting for age, gender, year of first diagnosis, insurance type, and Charlson comorbidity index, compared HRU across states (each state vs. the average of all other states.Of 201,322 IBS patients included, 77.2% were female. Mean age was 49.4 years. One in three patients had ≥3 distinct GI medical procedures or diagnostic tests; 50.1% visited a GI specialist. Significant HRU differences were observed in individual states compared to the national average. IBS-C patients had more medical visits, procedures, and pharmacy prescriptions for constipation/diarrhea than IBS patients without constipation.This study is the first to identify considerable regional variations in IBS healthcare across the US and to note a markedly higher HRU by IBS-C patients than by IBS patients without constipation. Identifying the reasons for these variations may improve quality of care and reduce the economic burden of IBS.

  16. Factors responsible for mortality variation in the United States: A latent variable analysis

    Directory of Open Access Journals (Sweden)

    Christopher Tencza

    2014-07-01

    Full Text Available Background: Factors including smoking, drinking, substance abuse, obesity, and health care have all been shown to affect health and longevity. The relative importance of each of these factors is disputed in the literature, and has been assessed through a number of methods. Objective: This paper uses a novel approach to identify factors responsible for interstate mortality variation. It identifies factors through their imprint on mortality patterns and can therefore identify factors that are difficult or impossible to measure directly, such as sensitive health behaviors. Methods: The analysis calculates age-standardized death rates by cause of death from 2000-2009 for white men and women separately. Only premature deaths between ages 20-64 are included. Latent variables responsible for mortality variation are then identified through a factor analysis conducted on a death-rate-by-state matrix. These unobserved latent variables are inferred from observed mortality data and interpreted based on their correlations with individual causes of death. Results: Smoking and obesity, substance abuse, and rural/urban residence are the three factors that make the largest contributions to state-level mortality variation among males. The same factors are at work for women but are less vividly revealed. The identification of factors is supported by a review of epidemiologic studies and strengthened by correlations with observable behavioral variables. Results are not sensitive to the choice of factor-analytic method used. Conclusions: The majority of interstate variation in mortality among white working-age adults in the United States is associated with a combination of smoking and obesity, substance abuse and rural/urban residence.

  17. Trends in Life Expectancy and Lifespan Variation by Educational Attainment: United States, 1990-2010.

    Science.gov (United States)

    Sasson, Isaac

    2016-04-01

    The educational gradient in life expectancy is well documented in the United States and in other low-mortality countries. Highly educated Americans, on average, live longer than their low-educated counterparts, who have recently seen declines in adult life expectancy. However, limiting the discussion on lifespan inequality to mean differences alone overlooks other dimensions of inequality and particularly disparities in lifespan variation. The latter represents a unique form of inequality, with higher variation translating into greater uncertainty in the time of death from an individual standpoint, and higher group heterogeneity from a population perspective. Using data from the National Vital Statistics System from 1990 to 2010, this is the first study to document trends in both life expectancy and S25--the standard deviation of age at death above 25--by educational attainment. Among low-educated whites, adult life expectancy declined by 3.1 years for women and by 0.6 years for men. At the same time, S25 increased by about 1.5 years among high school-educated whites of both genders, becoming an increasingly important component of total lifespan inequality. By contrast, college-educated whites benefited from rising life expectancy and record low variation in age at death, consistent with the shifting mortality scenario. Among blacks, adult life expectancy increased, and S25 plateaued or declined in nearly all educational attainment groups, although blacks generally lagged behind whites of the same gender on both measures. Documenting trends in lifespan variation can therefore improve our understanding of lifespan inequality and point to diverging trajectories in adult mortality across socioeconomic strata.

  18. Measure Guideline. Transitioning to a Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K. [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, A. [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-09-01

    This measure guideline provides information to help residential builders and retrofitters with the design, specification, selection, implementation, installation, and maintenance issues of transitioning from tank-type water heaters to tankless water heaters.

  19. Variation.

    Science.gov (United States)

    Hamilton City Board of Education (Ontario).

    Suggestions for studying the topic of variation of individuals and objects (balls) to help develop elementary school students' measurement, comparison, classification, evaluation, and data collection and recording skills are made. General suggestions of variables that can be investigated are made for the study of human variation. Twelve specific…

  20. The Spatial Variation of LURR and Seismic Tendency in Western United States

    Institute of Scientific and Technical Information of China (English)

    Zhang Huihui; Yin Xiangchu; Liang Naigang

    2005-01-01

    Load-Unload Response Ratio (LURR) is a new promising approach to earthquake prediction.In the previous years, a series of successful medium-term predictions have been made for strong earthquakes on the Chinese mainland using this method. In order to investigate whether the LURR method applies to different tectonic regimes, i.e., whether it is universal, the San Andreas Fault and its vicinities are chosen as the study region in this paper. The spatial variation of LURR in the western United States (30°~ 50°N, 100°~ 130°W) is studied in detail and the earthquake tendency in this region is discussed based on historic earthquake cases.

  1. The decline in living kidney donation in the United States: random variation or cause for concern?

    Science.gov (United States)

    Rodrigue, James R; Schold, Jesse D; Mandelbrot, Didier A

    2013-11-15

    The annual number of living kidney donors in the United States peaked at 6647 in 2004. The preceding decade saw a 120% increase in living kidney donation. However, since 2004, living kidney donation has declined in all but 1 year, resulting in a 13% decline in the annual number of living kidney donors from 2004 to 2011. The proportional decline in living kidney donation has been more pronounced among men, blacks, younger adults, siblings, and parents. In this article, we explore several possible explanations for the decline in living kidney donation, including an increase in medical unsuitability, an aging transplant patient population, financial disincentives, public policies, and shifting practice patterns, among others. We conclude that the decline in living donation is not merely reflective of random variation but one that warrants action by the transplant centers, the broader transplant community, and the state and national governments.

  2. Heater size effect on subcooled pool boiling of FC-72

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Rishi; Kim, Jungho [University of Maryland, College Park, MD (United States). Dept. of Mechanical Engineering

    2009-07-01

    Extensive research has been conducted on pool boiling using heaters larger than the capillary length. For large heaters and/or high gravity conditions, boiling is dominated by buoyancy, and the heat transfer is heater size independent. Much less is known about boiling on small heaters and at low gravity levels. The ratio of heater size L{sub h} to capillary length L{sub c} is an important parameter in the determination of heater size dependence on heat transfer. As the ratio L{sub h}/L{sub c} decreases due to a decrease in either heater size or gravity, surface tension forces become dominant. It is proposed that transition from buoyancy to surface tension dominated boiling occurs when the heater size and bubble departure diameter are of the same order. Previous work in variable gravity with flat surfaces has shown that the heat transfer was heater size independent only when the ratio L{sub h}/L{sub c} was considerably larger than 1. An array of 96 platinum resistance heater elements in a 10 x 10 configuration with individual elements 0.7 x 0.7 mm{sup 2} in size was used to vary heater size and measure the heat transfer. The threshold value of L{sub h}/L{sub c} above which pool boiling is heater size independent was found to be about 2.8. (author)

  3. 46 CFR 111.70-5 - Heater circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Heater circuits. 111.70-5 Section 111.70-5 Shipping... REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-5 Heater circuits. (a) If an enclosure for a... from a separate circuit, the heater circuit must be disconnected from its source of potential by...

  4. Genetic Variation of Sclerotinia sclerotiorum from Multiple Crops in the North Central United States.

    Science.gov (United States)

    Aldrich-Wolfe, Laura; Travers, Steven; Nelson, Berlin D

    2015-01-01

    Sclerotinia sclerotiorum is an important pathogen of numerous crops in the North Central region of the United States. The objective of this study was to examine the genetic diversity of 145 isolates of the pathogen from multiple hosts in the region. Mycelial compatibility groups (MCG) and microsatellite haplotypes were determined and analyzed for standard estimates of population genetic diversity and the importance of host and distance for genetic variation was examined. MCG tests indicated there were 49 different MCGs in the population and 52 unique microsatellite haplotypes were identified. There was an association between MCG and haplotype such that isolates belonging to the same MCG either shared identical haplotypes or differed at no more than 2 of the 12 polymorphic loci. For the majority of isolates, there was a one-to-one correspondence between MCG and haplotype. Eleven MCGs shared haplotypes. A single haplotype was found to be prevalent throughout the region. The majority of genetic variation in the isolate collection was found within rather than among host crops, suggesting little genetic divergence of S. sclerotiorum among hosts. There was only weak evidence of isolation by distance. Pairwise population comparisons among isolates from canola, dry bean, soybean and sunflower suggested that gene flow between host-populations is more common for some crops than others. Analysis of linkage disequilibrium in the isolates from the four major crops indicated primarily clonal reproduction, but also evidence of genetic recombination for isolates from canola and sunflower. Accordingly, genetic diversity was highest for populations from canola and sunflower. Distribution of microsatellite haplotypes across the study region strongly suggest that specific haplotypes of S. sclerotiorum are often found on multiple crops, movement of individual haplotypes among crops is common and host identity is not a barrier to gene flow for S. sclerotiorum in the north central United

  5. Genetic Variation of Sclerotinia sclerotiorum from Multiple Crops in the North Central United States

    Science.gov (United States)

    Aldrich-Wolfe, Laura; Travers, Steven; Nelson, Berlin D.

    2015-01-01

    Sclerotinia sclerotiorum is an important pathogen of numerous crops in the North Central region of the United States. The objective of this study was to examine the genetic diversity of 145 isolates of the pathogen from multiple hosts in the region. Mycelial compatibility groups (MCG) and microsatellite haplotypes were determined and analyzed for standard estimates of population genetic diversity and the importance of host and distance for genetic variation was examined. MCG tests indicated there were 49 different MCGs in the population and 52 unique microsatellite haplotypes were identified. There was an association between MCG and haplotype such that isolates belonging to the same MCG either shared identical haplotypes or differed at no more than 2 of the 12 polymorphic loci. For the majority of isolates, there was a one-to-one correspondence between MCG and haplotype. Eleven MCGs shared haplotypes. A single haplotype was found to be prevalent throughout the region. The majority of genetic variation in the isolate collection was found within rather than among host crops, suggesting little genetic divergence of S. sclerotiorum among hosts. There was only weak evidence of isolation by distance. Pairwise population comparisons among isolates from canola, dry bean, soybean and sunflower suggested that gene flow between host-populations is more common for some crops than others. Analysis of linkage disequilibrium in the isolates from the four major crops indicated primarily clonal reproduction, but also evidence of genetic recombination for isolates from canola and sunflower. Accordingly, genetic diversity was highest for populations from canola and sunflower. Distribution of microsatellite haplotypes across the study region strongly suggest that specific haplotypes of S. sclerotiorum are often found on multiple crops, movement of individual haplotypes among crops is common and host identity is not a barrier to gene flow for S. sclerotiorum in the north central United

  6. Materials for a Stirling engine heater head

    Science.gov (United States)

    Noble, J. E.; Lehmann, G. A.; Emigh, S. G.

    1990-01-01

    Work done on the 25-kW advanced Stirling conversion system (ASCS) terrestrial solar program in establishing criteria and selecting materials for the engine heater head and heater tubes is described. Various mechanisms contributing to incompatibility between materials are identified and discussed. Large thermal gradients, coupled with requirements for long life (60,000 h at temperature) and a large number of heatup and cooldown cycles (20,000) drive the design from a structural standpoint. The pressurized cylinder is checked for creep rupture, localized yielding, reverse plasticity, creep and fatigue damage, and creep ratcheting, in addition to the basic requirements for bust and proof pressure. In general, creep rupture and creep and fatigue interaction are the dominant factors in the design. A wide range of materials for the heater head and tubes was evaluated. Factors involved in the assessment were strength and effect on engine efficiency, reliability, and cost. A preliminary selection of Inconel 713LC for the heater head is based on acceptable structural properties but driven mainly by low cost. The criteria for failure, the structural analysis, and the material characteristics with basis for selection are discussed.

  7. Variation in low-frequency estimates of sound levels based on different units of analysis.

    Science.gov (United States)

    Hawkins, Russell S; Miksis-Olds, Jennifer L; Smith, Chad M

    2014-02-01

    The measurement and analysis of underwater sound is a complicated process because of the variable durations of contributing sources and constantly changing water column dynamics. Because the ambient sound distribution does not always follow a Gaussian structure and may be nonstationary in time, analysis over an extended period is required to accurately characterize the data. Utilizing recordings from the Indian Ocean, the temporal variation in ambient sound including transient signals was examined using multiple processing window lengths and subsampling intervals. Results illustrate the degree of uncertainty in sound levels based on different units of analysis. The average difference between sound level estimates in the 10-30 Hz band due to subsampling was 2 dB and as high as 4 dB. The difference in the full band (5-110 Hz) was as high as 6 dB. Longer averaging windows (200 vs 60 s) resulted in larger variations over different subsampling intervals. This work demonstrates how sampling protocols within a single dataset can influence results and acknowledges that comparative studies at the same location but with different sampling protocols can be substantial if signal processing parameters are not statistically accounted for to confirm interpretation of results and observed trends.

  8. Echinococcus equinus and Echinococcus granulosus sensu stricto from the United Kingdom: genetic diversity and haplotypic variation.

    Science.gov (United States)

    Boufana, Belgees; Lett, Wai San; Lahmar, Samia; Buishi, Imad; Bodell, Anthony J; Varcasia, Antonio; Casulli, Adriano; Beeching, Nicholas J; Campbell, Fiona; Terlizzo, Monica; McManus, Donald P; Craig, Philip S

    2015-02-01

    Cystic echinococcosis is endemic in Europe including the United Kingdom. However, information on the molecular epidemiology of Echinococcus spp. from the United Kingdom is limited. Echinococcus isolates from intermediate and definitive animal hosts as well as from human cystic echinococcosis cases were analysed to determine species and genotypes within these hosts. Echinococcus equinus was identified from horse hydatid isolates, cysts retrieved from captive UK mammals and copro-DNA of foxhounds and farm dogs. Echinococcus granulosus sensu stricto (s.s.) was identified from hydatid cysts of sheep and cattle as well as in DNA extracted from farm dog and foxhound faecal samples, and from four human cystic echinococcosis isolates, including the first known molecular confirmation of E. granulosus s.s. infection in a Welsh sheep farmer. Low genetic variability for E. equinus from various hosts and from different geographical locations was detected using the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), indicating the presence of a dominant haplotype (EQUK01). In contrast, greater haplotypic variation was observed for E. granulosus s.s. cox1 sequences. The haplotype network showed a star-shaped network with a centrally placed main haplotype (EgUK01) that had been reported from other world regions.

  9. Allergenic pollen season variations in the past two decades under changing climate in the United States.

    Science.gov (United States)

    Zhang, Yong; Bielory, Leonard; Mi, Zhongyuan; Cai, Ting; Robock, Alan; Georgopoulos, Panos

    2015-04-01

    Many diseases are linked with climate trends and variations. In particular, climate change is expected to alter the spatiotemporal dynamics of allergenic airborne pollen and potentially increase occurrence of allergic airway disease. Understanding the spatiotemporal patterns of changes in pollen season timing and levels is thus important in assessing climate impacts on aerobiology and allergy caused by allergenic airborne pollen. Here, we describe the spatiotemporal patterns of changes in the seasonal timing and levels of allergenic airborne pollen for multiple taxa in different climate regions at a continental scale. The allergenic pollen seasons of representative trees, weeds and grass during the past decade (2001-2010) across the contiguous United States have been observed to start 3.0 [95% Confidence Interval (CI), 1.1-4.9] days earlier on average than in the 1990s (1994-2000). The average peak value and annual total of daily counted airborne pollen have increased by 42.4% (95% CI, 21.9-62.9%) and 46.0% (95% CI, 21.5-70.5%), respectively. Changes of pollen season timing and airborne levels depend on latitude, and are associated with changes of growing degree days, frost free days, and precipitation. These changes are likely due to recent climate change and particularly the enhanced warming and precipitation at higher latitudes in the contiguous United States.

  10. HYDROGEOLOGICAL VARIATIONS OF GROUND WATER IN DIFFERENT GEOMARPHIC UNITS OF KRISHNA EASTERN DELTA, ANDHRA PRADESH

    Directory of Open Access Journals (Sweden)

    SITARAMA PRASAD KUDARAVALLI,

    2010-09-01

    Full Text Available The Krishna Eastern delta is located South of Vijayawada City in Andhra Pradesh. The area of the Krishna Eastern delta enclosed between Latitude 15042’N – 16042’ N and Longitude 80042’ E – 81036’ E. The present study is done on Krishna Eastern delta separately because the physiographic and lithological configuration of this part of the delta varies widely with that of the Western part. Moreover, the aquifer of this region has unique hydrochemical characteristics. In recent years the ground water in this region has been subjected to intensive exploitation for both irrigation and domestic purposes and accordingly high seasonal hydrochemical modulations were noticed in this part of the delta region. Kulakarni KM et.al. (1998 have studied drinking water salinity problem in Coastal Orissa. In this context a detailed study has been made to update the hydrogeochemical information of the aquifer system of this region. In addition to the earlier works carried out by Nageswara Rao, K. et.al. in the year 1979 and 1985. The details viz., land form locations in the delta region were taken from the study. The seasonal variation of groundwater quality in different geological units in Krishna Eastern Delta has been subjected to study by collecting water samples in different open wells in the study area and subjecting them to detailed chemical analysis. This data has been utilized to draw contour diagrams of different water quality parameters for different seasons. The present study is an attempt to visualize the spatial water quality variations in different geomorphic units present in the deltaic environment. The chemical parameter of Electrical Conductivity was taken as the prime parameter to focus the seasonal spatial variations of different geomorphic forms and the data was used to draw contours for different seasons. The detailed studies of Ground Water Department, District Office were also studied in many unpublished reports for understanding

  11. Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    David Yuill

    2008-06-30

    design was then implemented on a prototype heater that was being developed simultaneously with the controller development. (The prototype's geometry and components are based on a currently marketed heater, but several improvements have been made.) The MPC's temperature control performance was a vast improvement over the existing controller. With a benchmark for superior control performance established, five additional control methods were tested. One problem with MPC control is that it was found to be extremely difficult to implement in a TWH, so that it is unlikely to be widely adopted by manufacturers. Therefore the five additional control methods were selected based on their simplicity; each could be implemented by a typical manufacturer. It was found that one of these methods performed as well as MPC, or even better under many circumstances. This method uses a Feedback-Compensated Feed-Forward algorithm that was developed for this project. Due to its simplicity and excellent performance this method was selected as the controller of choice. A final higher-capacity prototype heater that uses Feedback-Compensated Feed-Forward control was constructed. This prototype has many improvements over the currently marketed heaters: (1) excellent control; (2) a modular design that allows for different capacity heaters to be built easily; (3) built-in fault detection and diagnosis; (4) a secondary remote user-interface; and (5) a TRIAC switching algorithm that will minimize 'flicker factor'. The design and engineering of this prototype unit will allow it to be built without an increase in cost, compared with the currently marketed heater. A design rendering of the new product is shown below. It will be launched with a new marketing campaign by Keltech in early 2009.

  12. Exergetic performance evaluation and parametric studies of solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, M.K.; Kaushik, S.C. [Centre for Energy Studies, Indian Institute of Technology, Delhi 110016 (India)

    2008-11-15

    The present study aims to establish the optimal performance parameters for the maximum exergy delivery during the collection of solar energy in a flat-plate solar air heater. The procedure to determine optimum aspect ratio (length to width ratio of the absorber plate) and optimum duct depth (the distance between the absorber and the bottom plates) for maximum exergy delivery has been developed. It is known that heat energy gain and blower work increase monotonically with mass flow rate, while the temperature of air decreases; therefore, it is desirable to incorporate the quality of heat energy collected and the blower work. First it is proved analytically that the optimum exergy output, neglecting blower work, and the corresponding mass flow rate depend on the inlet temperature of air. The energy and exergy output rates of the solar air heater were evaluated for various values of collector aspect ratio (AR) of the collector, mass flow rate per unit area of the collector plate (G) and solar air heater duct depth (H). Results have been presented to discuss the effects of G, AR and H on the energy and exergy output rates of the solar air heater. The energy output rate increases with G and AR, and decreases with H and the inlet temperature of air. The exergy-based evaluation criterion shows that performance is not a monotonically increasing function of G and AR, and a decreasing function of H and inlet temperature of air. Based on the exergy output rate, it is found that there must be an optimum inlet temperature of air and a corresponding optimum G for any value of AR and H. For values of G lesser than optimal corresponding to inlet temperature of air equals to ambient, higher exergy output rate is achieved for the low value of duct depth and high AR in the range of parameters investigated. If G is high, for an application requiring less temperature increase, then either low AR or high H would give higher exergy output rate. (author)

  13. Variation Character of Grain Yield per Unit Area in Main Grain-producing Area of Northeast China

    Institute of Scientific and Technical Information of China (English)

    CHENG Yeqing; ZHANG Pingyu; ZHANG Huimin

    2007-01-01

    Based on the surveys and the statistic data during 1980-2003, the variation character of grain yield per unit area in Northeast China and its main factors have been discussed by the methods of statistics and grey correlation analysis. The results show that: 1) the grain yield per unit area has been taking on an increasing trend in the recent 20 years. It increased from 2519.80kg/ha in 1980 to 4216.11 kg/ha in 2003, with an increasing rate of 67.32%; 2) the variation of grain yield per unit area is considerably prominent and its range is also very great, with the maximal increase rate of 42.59% and maximal decrease rate of 21.13%, respectively, which are far above the whole Chinese average level; 3) the variation of main crops' yield per unit area is remarkable, which takes on the character that the yield of corn is much higher than that of soybean and rice; and 4) the grey correlation analysis shows that the most important factors impacting the variation of grain yield per unit area are the total power of agricultural machinery, the consumption of chemical fertilizer and effective irrigated area. However, the influence of natural disaster and income level should not be ignored. Effective ways to improve grain yield per unit area are to construct farmland improvement groundwork, reclaim the middle- and low-yield farmland, etc.

  14. Asymmetric Pentagonal Metal Meshes for Flexible Transparent Electrodes and Heaters.

    Science.gov (United States)

    Lordan, Daniel; Burke, Micheal; Manning, Mary; Martin, Alfonso; Amann, Andreas; O'Connell, Dan; Murphy, Richard; Lyons, Colin; Quinn, Aidan J

    2017-02-08

    Metal meshes have emerged as an important class of flexible transparent electrodes. We report on the characteristics of a new class of asymmetric meshes, tiled using a recently discovered family of pentagons. Micron-scale meshes were fabricated on flexible polyethylene terephthalate substrates via optical lithography, metal evaporation (Ti 10 nm, Pt 50 nm), and lift-off. Three different designs were assessed, each with the same tessellation pattern and line width (5 μm), but with different sizes of the fundamental pentagonal unit. Good mechanical stability was observed for both tensile strain and compressive strain. After 1000 bending cycles, devices subjected to tensile strain showed fractional resistance increases in the range of 8-17%, while devices subjected to compressive strain showed fractional resistance increases in the range of 0-7%. The performance of the pentagonal metal mesh devices as visible transparent heaters via Joule heating was also assessed. Rapid response times (∼15 s) at low bias voltage (≤5 V) and good thermal resistance characteristics (213-258 °C cm(2)/W) were found using measured thermal imaging data. Deicing of an ice-bearing glass coupon on top of the transparent heater was also successfully demonstrated.

  15. Analysis Approach to Improve Star Rating Of Water Heater

    Directory of Open Access Journals (Sweden)

    Sujata Dabhade

    2014-07-01

    Full Text Available Electric Water Heaters are widely used all over the world that can be categorized in two types i.e. Instant Water Heaters & Storage type Water Heaters. The energy consumption for 6 liter water heaters is much higher in the storage type of water heater. As energy is an important factor for economic development of country, therefore there is need to save the energy which implies the focus to use Storage type Water Heaters. In 6 Liter water heater, Existing model converting from 4 star rating to 5 star rating by thermal analysis & insulation. After the theoretical calculation of thickness of glass wool is the practical testing of product with BEE norms & got results for 5 Star Calculation. Finally we are doing the thermal analysis for theoretical & practical verification of the product

  16. Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

    2012-07-01

    Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

  17. Variation in use of antipsychotic medications in nursing homes in the United States: A systematic review.

    Science.gov (United States)

    Cioltan, Hannah; Alshehri, Samah; Howe, Carol; Lee, Jeannie; Fain, Mindy; Eng, Howard; Schachter, Kenneth; Mohler, Jane

    2017-01-26

    The use of antipsychotic medications (APMs) in nursing home residents in the U.S. is an increasingly prominent issue and has been associated with increased risk of hospitalization, cardiovascular events, hip fractures, and mortality, among other adverse health events. The Food and Drug Administration has placed a black box warning on these drugs, specifying that they are not meant for residents with dementia, and has asked providers to review their treatment plans. The purpose of this systematic PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses)-based review was to summarize original research studies on facility level characteristics contributing to the use of antipsychotics in nursing homes across the United States, in order to investigate the variation of use. We searched Ovid Medline, Embase, Cochrane Library, Web of Science, CINAHL, PsycInfo, and Sociological Abstracts. Articles were selected according to the following criteria: (1) Population of interest: older adults (≥60 years of age) residing in nursing homes (not home-based or inpatient hospital settings) in the U.S. (2) Receiving APMs, typical and/or atypical. Specifically excluded were studies of psychotropic medications such as antidepressants, benzodiazepines, anxiolytics, hypnotics, mood stabilizers, and stimulants. All study designs were considered, though reviews, editorials, letters to the editor and opinion pieces were excluded. An expert consultant panel was consulted to categorize facility characteristics into domains and determine possible etiologies of APM use based upon each characteristic. Nineteen observational studies, both quantitative and qualitative, published from 2000 to 2015, met full inclusion criteria and were included in this review. APM use varied based on multiple facility characteristics across several domains: 1) physical, 2) staffing, 3) occupancy, 4) market, and 5) quality. Variation in use of APMs in U.S. nursing homes based upon facility

  18. Geographic variation of Trypanosoma cruzi discrete typing units from Triatoma infestans at different spatial scales.

    Science.gov (United States)

    Fernández, María Del Pilar; Cecere, María Carla; Lanati, Leonardo Alejandro; Lauricella, Marta Alicia; Schijman, Alejandro Gabriel; Gürtler, Ricardo Esteban; Cardinal, Marta Victoria

    2014-12-01

    We assessed the diversity and distribution of Trypanosoma cruzi discrete typing units (DTU) in Triatoma infestans populations and its association with local vector-borne transmission levels at various geographic scales. At a local scale, we found high predominance (92.4%) of TcVI over TcV in 68 microscope-positive T. infestans collected in rural communities in Santiago del Estero province in northern Argentina. TcV was more often found in communities with higher house infestation prevalence compatible with active vector-borne transmission. Humans and dogs were the main bloodmeal sources of the TcV- and TcVI-infected bugs. At a broader scale, the greatest variation in DTU diversity was found within the Argentine Chaco (227 microscope-positive bugs), mainly related to differences in equitability between TcVI and TcV among study areas. At a country-wide level, a meta-analysis of published data revealed clear geographic variations in the distribution of DTUs across countries. A correspondence analysis showed that DTU distributions in domestic T. infestans were more similar within Argentina (dominated by TcVI) and within Bolivia (where TcI and TcV had similar relative frequencies), whereas large heterogeneity was found within Chile. DTU diversity was lower in the western Argentine Chaco region and Paraguay (D=0.14-0.22) than in the eastern Argentine Chaco, Bolivia and Chile (D=0.20-0.68). Simultaneous DTU identifications of T. cruzi-infected hosts and triatomines across areas differing in epidemiological status are needed to shed new light on the structure and dynamics of parasite transmission cycles.

  19. Anti-freezing performance research of dry type shell-tube heat exchanger for air source heat pump water chiller-heater unit%空气源热泵冷(热)水机组用干式壳管换热器防冻性能研究

    Institute of Scientific and Technical Information of China (English)

    张龙爱; 陈忠杰; 王传华

    2012-01-01

    针对空气源热泵冷(热)水机组运行中可能出现的干式壳管换热器冻裂问题,分析其被冻裂的主要因素,并且对壳管换热器冻裂的关键因素——蒸发压力过低的原因进行分析.基于分析结果,对壳管换热器的设计进行改进,同时对低流量保护点进行试验验证.%Aiming at the frost-cracking problem of the dry type shell-tube heat exchanger for air source heat pump water chiller-heater unit, the main influencing factors are analyzed. The key reason of shell-tube heat exchanger frost-cracking is analyzed that is too low evaporating pressure. The design of shell-tube heat exchanger is improved based on the analysis results, and the limited flow rate for protection of flow switch is verified by the test.

  20. Variation in Emergency Department vs Internal Medicine Excess Charges in the United States.

    Science.gov (United States)

    Xu, Tim; Park, Angela; Bai, Ge; Joo, Sarah; Hutfless, Susan M; Mehta, Ambar; Anderson, Gerard F; Makary, Martin A

    2017-08-01

    (median, 5.0; IQR, 3.5-6.7 for ≥20% uninsured), and location (median, 5.3; IQR, 3.8-6.8 for the southeastern United States). Across hospitals, there is wide variation in excess charges on ED services, which are often priced higher than internal medicine services. Our results inform policy efforts to protect uninsured and out-of-network patients from highly variable pricing.

  1. The Use of Oceanic Indices Variations Due to Climate Change to Predict Annual Discharge Variations in Northeastern United States

    Science.gov (United States)

    Berton, R.; Shaw, S. B.; Chandler, D. G.; Driscoll, C. T.

    2014-12-01

    Climatic change affects streamflow in watersheds with winter snowpack and an annual snowmelt hydrograph. In the northeastern US, changes in streamflow are driven by both the advanced timing of snowmelt and increasing summer precipitation. Projections of climate for the region in the 21st century is for warmer winters and wetter summers. Water planners need to understand future changes in flow metrics to determine if the current water resources are capable of fulfilling future demands or adapting to future changes in climate. The study of teleconnection patterns between oceanic indices variations and hydrologic variables may help improve the understanding of future water resources conditions in a watershed. The purpose of this study is to evaluate the correlation between oceanic indices and discharge variations in the Merrimack Watershed. The Merrimack Watershed is the fourth largest basin in New England which drains much of New Hampshire and northeastern portions of Massachusetts, USA. Variations in sea surface temperature (SST) and sea level pressure (SLP) are defined by the Atlantic Multi-decadal Oscillation (AMO) and the North Atlantic Oscillation (NAO), respectively. We hypothesize that temporal changes in discharge are related to AMO and NAO variations since precipitation and discharge are highly correlated in the Merrimack. The Merrimack Watershed consists of undisturbed (reference) catchments and disturbed (developed) basins with long stream gauge records (> 100 years). Developed basins provide an opportunity to evaluate the impacts of river regulation and land development on teleconnection patterns as well as changing climate. Time series of AMO and NAO indices over the past 150 years along with Merrimack annual precipitation and discharge time series have shown a 1 to 2-year watershed hydrologic memory; higher correlation between Merrimack‎ annual precipitation and discharge with AMO and NAO are observed when a 1 to 2-year lag is given to AMO and NAO

  2. Solar Air Heaters with Thermal Heat Storages

    Directory of Open Access Journals (Sweden)

    Abhishek Saxena

    2013-01-01

    Full Text Available Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has been carried out to rate the various thermal energy storage commonly used in solar air heaters. During the investigations rock bed storages have been found to be low type thermal heat storage, while phase change materials have been found to be high heat thermal storages. Besides this, a few other heat storing materials have been studied and discussed for lower to higher ratings in terms of thermal performance purposely for solar heaters.

  3. Improving the Gas Instantaneous Water Heaters Performances

    Directory of Open Access Journals (Sweden)

    Nasir Kloub

    2005-01-01

    Full Text Available This study presents a study of a theoretical and practical investigation of the gas Instantaneous (Tankless water Heaters performance. The results allow us to obtain realistic values of the control system in the various capacities gaseous flowing water heaters. The objective of this work is to study the operation of the plans in the field of controlling and checking low capacity gaseous flowing water in order to choose the proper plan of the logical values and measures for these equipments that may be used in industrial conditions. Also results of the work proved to be accurate. A design of the control system was made. The results of the practical experiment of the control system were similar to the arithmetic results.

  4. Single-heater test final report

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S. C.; Buscheck, T. A.; DeLoach, L. D.; Lin, W.; Ramirez, A. I.

    1998-09-01

    The Single-Heater Test (SHT) was one phase of the field-scale thermal testing program of the Yucca Mountain Site Characterization Project. The primary purpose of the SHT was to study the thermomechanical (TM) behavior of the densely welded, non-lithophysal Topopah Spring tuff at the Exploratory Studies Facility. The SHT was also used as a shake-down for testing thermal-hydrologic-chemical-mechanical processes in situ, testing that will be conducted in the Drift-Scale Test. In the SHT, a line-heat source 5-m long was emplaced in a pillar and used to heat the pillar for approximately nine months. The thermal field was relatively cylindrical about the line-heat source. The heater was turned off after nine months of heating, and the rock mass was monitored during the cool-down for another nine months, until May 28, 1997, when the test was terminated.

  5. AWSWAH - the heat pipe solar water heater

    Energy Technology Data Exchange (ETDEWEB)

    Akyurt, M.

    1986-01-01

    An all weather heat pipe solar water heater (AWSWAH) comprising a collector of 4 m/sup 2/ (43 ft/sup 2/) and a low profile water tank of 160 liters (42 gal.) was developed. A single heat pipe consisting of 30 risers and two manifolds in the evaporator and a spiral condenser was incorporated into the AWSWAH. Condensate metering was done by synthetic fiber wicks. The AWSWAH was tested alongside two conventional solar water heaters of identical dimensions, an open loop system and a closed loop system. It was found that the AWSWAH was an average of 50% more effective than the open system in the temperature range 30-90 /sup 0/C (86-194 /sup 0/F). The closed loop system was the least efficient of the three systems.

  6. Mendelian breeding units versus standard sampling strategies: Mitochondrial DNA variation in southwest Sardinia

    Science.gov (United States)

    Sanna, Daria; Pala, Maria; Cossu, Piero; Dedola, Gian Luca; Melis, Sonia; Fresu, Giovanni; Morelli, Laura; Obinu, Domenica; Tonolo, Giancarlo; Secchi, Giannina; Triunfo, Riccardo; Lorenz, Joseph G.; Scheinfeldt, Laura; Torroni, Antonio; Robledo, Renato; Francalacci, Paolo

    2011-01-01

    We report a sampling strategy based on Mendelian Breeding Units (MBUs), representing an interbreeding group of individuals sharing a common gene pool. The identification of MBUs is crucial for case-control experimental design in association studies. The aim of this work was to evaluate the possible existence of bias in terms of genetic variability and haplogroup frequencies in the MBU sample, due to severe sample selection. In order to reach this goal, the MBU sampling strategy was compared to a standard selection of individuals according to their surname and place of birth. We analysed mitochondrial DNA variation (first hypervariable segment and coding region) in unrelated healthy subjects from two different areas of Sardinia: the area around the town of Cabras and the western Campidano area. No statistically significant differences were observed when the two sampling methods were compared, indicating that the stringent sample selection needed to establish a MBU does not alter original genetic variability and haplogroup distribution. Therefore, the MBU sampling strategy can be considered a useful tool in association studies of complex traits. PMID:21734814

  7. Mendelian breeding units versus standard sampling strategies: mitochondrial DNA variation in southwest Sardinia

    Directory of Open Access Journals (Sweden)

    Daria Sanna

    2011-01-01

    Full Text Available We report a sampling strategy based on Mendelian Breeding Units (MBUs, representing an interbreeding group of individuals sharing a common gene pool. The identification of MBUs is crucial for case-control experimental design in association studies. The aim of this work was to evaluate the possible existence of bias in terms of genetic variability and haplogroup frequencies in the MBU sample, due to severe sample selection. In order to reach this goal, the MBU sampling strategy was compared to a standard selection of individuals according to their surname and place of birth. We analysed mitochondrial DNA variation (first hypervariable segment and coding region in unrelated healthy subjects from two different areas of Sardinia: the area around the town of Cabras and the western Campidano area. No statistically significant differences were observed when the two sampling methods were compared, indicating that the stringent sample selection needed to establish a MBU does not alter original genetic variability and haplogroup distribution. Therefore, the MBU sampling strategy can be considered a useful tool in association studies of complex traits.

  8. Water heaters subject to new regulations.

    Science.gov (United States)

    Clarke, Alan

    2014-06-01

    On 26 September 2015 the Ecodesign and Energy Labelling Directives for water heaters (Lot 2) come into force, meaning that water-heating products sold in the UK and other countries in the European Economic Area will need to meet minimum energy performance criteria in order to be legally placed on the market, and will require an energy label. Here Alan Clarke, technical support manager at Heatrae Sadia, explains more.

  9. Field Monitoring Protocol: Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Earle, L.; Christensen, D.; Maguire, J.; Wilson, E.; Hancock, E.

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  10. Field Monitoring Protocol. Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maguire, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, C. E. [Mountain Energy Partnership, Longmont, CO (United States)

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  11. Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in "Brassica rapa" Fast Plants

    Science.gov (United States)

    Batzli, Janet M.; Smith, Amber R.; Williams, Paul H.; McGee, Seth A.; Dosa, Katalin; Pfammatter, Jesse

    2014-01-01

    Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question "What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev)," we developed a 4-wk unit for an inquiry-based laboratory…

  12. Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in "Brassica rapa" Fast Plants

    Science.gov (United States)

    Batzli, Janet M.; Smith, Amber R.; Williams, Paul H.; McGee, Seth A.; Dosa, Katalin; Pfammatter, Jesse

    2014-01-01

    Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question "What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev)," we developed a 4-wk unit for an inquiry-based laboratory…

  13. Detection of Historical and Future Precipitation Variations and Extremes Over the Continental United States

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Bruce T. [Boston Univ., MA (United States)

    2015-12-11

    Problem: The overall goal of this proposal is to detect observed seasonal-mean precipitation variations and extreme event occurrences over the United States. Detection, e.g. the process of demonstrating that an observed change in climate is unusual, first requires some means of estimating the range of internal variability absent any external drivers. Ideally, the internal variability would be derived from the observations themselves, however generally the observed variability is a confluence of both internal variability and variability in response to external drivers. Further, numerical climate models—the standard tool for detection studies—have their own estimates of intrinsic variability, which may differ substantially from that found in the observed system as well as other model systems. These problems are further compounded for weather and climate extremes, which as singular events are particularly ill-suited for detection studies because of their infrequent occurrence, limited spatial range, and underestimation within global and even regional numerical models. Rationale: As a basis for this research we will show how stochastic daily-precipitation models—models in which the simulated interannual-to-multidecadal precipitation variance is purely the result of the random evolution of daily precipitation events within a given time period—can be used to address many of these issues simultaneously. Through the novel application of these well-established models, we can first estimate the changes/trends in various means and extremes that can occur even with fixed daily-precipitation characteristics, e.g. that can occur simply as a result of the stochastic evolution of daily weather events within a given climate. Detection of a change in the observed climate—either naturally or anthropogenically forced—can then be defined as any change relative to this stochastic variability, e.g. as changes/trends in the means and extremes that could only have occurred

  14. Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

    OpenAIRE

    Xu Ji; Ming Li; Weidong Lin; Tufeng Zheng; Yunfeng Wang

    2015-01-01

    The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to ...

  15. Infrared Heater Used in Qualification Testing of International Space Station Radiators

    Science.gov (United States)

    Ziemke, Robert A.

    2004-01-01

    Two heat rejection radiator systems for the International Space Station (ISS) have undergone thermal vacuum qualification testing at the NASA Glenn Research Center (GRC), Plum Brook Station, Sandusky, Ohio. The testing was performed in the Space Power Facility (SPF), the largest thermal vacuum chamber in the world. The heat rejection system radiator was tested first; it removes heat from the ISS crew living quarters. The second system tested was the photovoltaic radiator (PVR), which rejects heat from the ISS photovoltaic arrays and the electrical power-conditioning equipment. The testing included thermal cycling, hot- and cold-soaked deployments, thermal gradient deployments, verification of the onboard heater controls, and for the PVR, thermal performance tests with ammonia flow. Both radiator systems are orbital replacement units for ease of replacement on the ISS. One key to the success of these tests was the performance of the infrared heater system. It was used in conjunction with a gaseous-nitrogen-cooled cryoshroud in the SPF vacuum chamber to achieve the required thermal vacuum conditions for the qualification tests. The heater, which was designed specifically for these tests, was highly successful and easily met the test requirements. This report discusses the heating requirements, the heater design features, the design approach, and the mathematical basis of the design.

  16. Insulated conductor temperature limited heater for subsurface heating coupled in a three-phase WYE configuration

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Sandberg, Chester Ledlie (Palo Alto, CA)

    2010-11-09

    A heating system for a subsurface formation is described. The heating system includes a first heater, a second heater, and a third heater placed in an opening in the subsurface formation. Each heater includes: an electrical conductor; an insulation layer at least partially surrounding the electrical conductor; and an electrically conductive sheath at least partially surrounding the insulation layer. The electrical conductor is electrically coupled to the sheath at a lower end portion of the heater. The lower end portion is the portion of the heater distal from a surface of the opening. The first heater, the second heater, and the third heater are electrically coupled at the lower end portions of the heaters. The first heater, the second heater, and the third heater are configured to be electrically coupled in a three-phase wye configuration.

  17. Impact of kerosene space heaters on indoor air quality.

    Science.gov (United States)

    Hanoune, B; Carteret, M

    2015-09-01

    In recent years, the use of kerosene space heaters as additional or principal heat source has been increasing, because these heaters allow a continuous control on the energy cost. These devices are unvented, and all combustion products are released into the room where the heaters are operated. The indoor air quality of seven private homes using wick-type or electronic injection-type kerosene space heaters was investigated. Concentrations of CO, CO2, NOx, formaldehyde and particulate matter (0.02-10 μm) were measured, using time-resolved instruments when available. All heaters tested are significant sources of submicron particles, NOx and CO2. The average NO2 and CO2 concentrations are determined by the duration of use of the kerosene heaters. These results stress the need to regulate the use of unvented combustion appliances to decrease the exposure of people to air contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Effect of Random Thermal Spikes on Stirling Convertor Heater Head Reliability

    Science.gov (United States)

    Shah, Ashwin R.; Korovaichuk, Igor; Halford, Gary R.

    2004-01-01

    Onboard radioisotope power systems being developed to support future NASA exploration missions require reliable design lifetimes of up to 14 yr and beyond. The structurally critical heater head of the high-efficiency developmental Stirling power convertor has undergone extensive computational analysis of operating temperatures (up to 650 C), stresses, and creep resistance of the thin-walled Inconel 718 bill of material. Additionally, assessment of the effect of uncertainties in the creep behavior of the thin-walled heater head, the variation in the manufactured thickness, variation in control temperature, and variation in pressure on the durability and reliability were performed. However, it is possible for the heater head to experience rare incidences of random temperature spikes (excursions) of short duration. These incidences could occur randomly with random magnitude and duration during the desired mission life. These rare incidences could affect the creep strain rate and therefore the life. The paper accounts for these uncertainties and includes the effect of such rare incidences, random in nature, on the reliability. The sensitivities of variables affecting the reliability are quantified and guidelines developed to improve the reliability are outlined. Furthermore, the quantified reliability is being verified with test data from the accelerated benchmark tests being conducted at the NASA Glenn Research Center.

  19. Prediction of heater power distribution in radiative cylindrical furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, M.; Dilber, I.; Torok, D.

    1999-07-01

    In the design of long radiative cylindrical furnaces, it is important to control the temperature variation along the furnace walls and consequently the temperature distribution in the processed material by selectively adjusting the power input to heater rods located circumferentially around the furnace walls. The heaters are grouped in zones located at different axial locations. By adjusting the power to each zone a specified temperature distribution along the furnace can be attained. The radiative interchange between different axial zones of the furnace affects the temperature distribution; this interchange is also impacted by the shadowing caused by the presence of the load, i.e. the processed material. A desired temperature distribution can only be achieved by selectively changing the power input to the heaters. For an a priori assessment of the commercial viability of using process friendly temperature distributions, it is necessary to determine: (a) the maximum power demand from each zone; (b) if active cooling is inevitable and (c) the bounds on temperature distribution that can be achieved without active cooling. It is therefore extremely useful to be able to predict the input power distribution for achieving desired furnace temperature profiles. For a given power input, the temperature distribution inside the furnace could be obtained by using a general purpose Computational Fluid Dynamics (CFD) software, such as FIDAP. A new methodology is developed within the framework of FIDAP software to eliminate the manual trial and error method. The method is based on obtaining the sensitivity of the temperature at the desired locations of the furnace as a function of the power input to the heating elements. Using these sensitivity coefficients, an iterative scheme is designed to adjust the boundary conditions (power to the heating elements in this case) based on the discrepancy of the solution temperatures from the desired temperature distribution. For each of these

  20. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-02-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads.

  1. Service configuration, unit characteristics and variation in intervention rates in a national sample of obstetric units in England: an exploratory analysis.

    Science.gov (United States)

    Rowe, Rachel E; Townend, John; Brocklehurst, Peter; Knight, Marian; Macfarlane, Alison; McCourt, Christine; Newburn, Mary; Redshaw, Maggie; Sandall, Jane; Silverton, Louise; Hollowell, Jennifer

    2014-05-29

    To explore whether service configuration and obstetric unit (OU) characteristics explain variation in OU intervention rates in 'low-risk' women. Ecological study using funnel plots to explore unit-level variations in adjusted intervention rates and simple linear regression, stratified by parity, to investigate possible associations between unit characteristics/configuration and adjusted intervention rates in planned OU births. Characteristics considered: OU size, presence of an alongside midwifery unit (AMU), proportion of births in the National Health Service (NHS) trust planned in midwifery units or at home and midwifery 'under' staffing. 36 OUs in England. 'Low-risk' women with a 'term' pregnancy planning vaginal birth in a stratified, random sample of 36 OUs. Adjusted rates of intrapartum caesarean section, instrumental delivery and two composite measures capturing birth without intervention ('straightforward' and 'normal' birth). Funnel plots showed unexplained variation in adjusted intervention rates. In NHS trusts where proportionately more non-OU births were planned, adjusted intrapartum caesarean section rates in the planned OU births were significantly higher (nulliparous: R(2)=31.8%, coefficient=0.31, p=0.02; multiparous: R(2)=43.2%, coefficient=0.23, p=0.01), and for multiparous women, rates of 'straightforward' (R(2)=26.3%, coefficient=-0.22, p=0.01) and 'normal' birth (R(2)=17.5%, coefficient=0.24, p=0.01) were lower. The size of the OU (number of births), midwifery 'under' staffing levels (the proportion of shifts where there were more women than midwives) and the presence of an AMU were associated with significant variation in some interventions. Trusts with greater provision of non-OU intrapartum care may have higher intervention rates in planned 'low-risk' OU births, but at a trust level this is likely to be more than offset by lower intervention rates in planned non-OU births. Further research using high quality data on unit characteristics and

  2. Crypto heater:a design fiction

    OpenAIRE

    Lindley, Joseph

    2015-01-01

    This proposal is to exhibit the work named Crypto Heater which is part of a design fiction [c.f 1,5,8:30] series intended to explore a near future world in which cryptographic currencies such as Bitcoin [6] have become commonplace. This work opens up space for discussion about the activities of the distributed peer-to-peer network of so-called "miners" that ensure the security of the Bitcoin network and regulate the supply of new currency in the Bitcoin economy. The physical part of the work ...

  3. The Industrial Design of Water Heater

    Institute of Scientific and Technical Information of China (English)

    张萌萌

    2014-01-01

    The design was inspired by the understanding to the fine life understanding of life, relaxed requirement and under-standing of fashion. Each link of easy life present in the water heater design. The principle of"artappliances, life"brand phi-losophy, refined and understated elegance is the core essence, is also the brand logo. In the"draw the fine life inspiration, the core brand design language create eternal artistic quality", every product tothe interpretation of home life art trend, to embody the elegant life style annotation and experience, committed to the urban elites to create exquisitelife style.

  4. Experimental Creep Life Assessment for the Advanced Stirling Convertor Heater Head

    Science.gov (United States)

    Krause, David L.; Kalluri, Sreeramesh; Shah, Ashwin R.; Korovaichuk, Igor

    2010-01-01

    The United States Department of Energy is planning to develop the Advanced Stirling Radioisotope Generator (ASRG) for the National Aeronautics and Space Administration (NASA) for potential use on future space missions. The ASRG provides substantial efficiency and specific power improvements over radioisotope power systems of heritage designs. The ASRG would use General Purpose Heat Source modules as energy sources and the free-piston Advanced Stirling Convertor (ASC) to convert heat into electrical energy. Lockheed Martin Corporation of Valley Forge, Pennsylvania, is integrating the ASRG systems, and Sunpower, Inc., of Athens, Ohio, is designing and building the ASC. NASA Glenn Research Center of Cleveland, Ohio, manages the Sunpower contract and provides technology development in several areas for the ASC. One area is reliability assessment for the ASC heater head, a critical pressure vessel within which heat is converted into mechanical oscillation of a displacer piston. For high system efficiency, the ASC heater head operates at very high temperature (850 C) and therefore is fabricated from an advanced heat-resistant nickel-based superalloy Microcast MarM-247. Since use of MarM-247 in a thin-walled pressure vessel is atypical, much effort is required to assure that the system will operate reliably for its design life of 17 years. One life-limiting structural response for this application is creep; creep deformation is the accumulation of time-dependent inelastic strain under sustained loading over time. If allowed to progress, the deformation eventually results in creep rupture. Since creep material properties are not available in the open literature, a detailed creep life assessment of the ASC heater head effort is underway. This paper presents an overview of that creep life assessment approach, including the reliability-based creep criteria developed from coupon testing, and the associated heater head deterministic and probabilistic analyses. The approach also

  5. Micro Ethanol Sensors with a Heater Fabricated Using the Commercial 0.18 μm CMOS Process

    Directory of Open Access Journals (Sweden)

    Wei-Zhen Liao

    2013-09-01

    Full Text Available The study investigates the fabrication and characterization of an ethanol microsensor equipped with a heater. The ethanol sensor is manufactured using the commercial 0.18 µm complementary metal oxide semiconductor (CMOS process. The sensor consists of a sensitive film, a heater and interdigitated electrodes. The sensitive film is zinc oxide prepared by the sol-gel method, and it is coated on the interdigitated electrodes. The heater is located under the interdigitated electrodes, and it is used to supply a working temperature to the sensitive film. The sensor needs a post-processing step to remove the sacrificial oxide layer, and to coat zinc oxide on the interdigitated electrodes. When the sensitive film senses ethanol gas, the resistance of the sensor generates a change. An inverting amplifier circuit is utilized to convert the resistance variation of the sensor into the output voltage. Experiments show that the sensitivity of the ethanol sensor is 0.35 mV/ppm.

  6. Temperature distributions in trapezoidal built in storage solar water heaters with/without phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Tarhan, Sefa; Yardim, M. Hakan [Department of Farm Machinery, Faculty of Agriculture, Gaziosmanpasa University, Tasliciftlik Yerleskesi, 60240 Tokat (Turkey); Sari, Ahmet [Department of Chemistry, Faculty of Arts and Sciences, Gaziosmanpasa University, Tasliciftlik Yerleskesi, 60240 Tokat (Turkey)

    2006-09-15

    Built in storage solar water heaters (BSSWHs) have been recognized for their more compact constructions and faster solar gain than conventional solar water heaters, however, their water temperatures quickly go down during the cooling period. A trapezoidal BSSWH without PCM storage unit was used as the control heater (reference) to investigate the effect of two differently configured PCM storage units on the temperature distributions in water tanks. In the first design, myristic acid was filled into the PCM storage tank, which also served as an absorbing plate. In the second design, lauric acid was filled into the PCM storage tank, which also served as a baffle plate. The water temperature changes were followed by five thermocouples placed evenly and longitudinally into each of the three BSSWHs. The effects of the PCMs on the water temperature distributions depended on the configuration of the PCM storage unit and the longitudinal position in the water tanks. The use of lauric acid lowered the values of the peak temperatures by 15% compared to the control heater at the upper portion of the water tanks because of the low melting temperature of lauric acid, but it did not have any consistent effect on the retention of the water temperatures during the cooling period. The ability of the myristic acid storage unit to retain the water temperatures got more remarkable, especially at the middle portion of the water tank. The myristic acid storage increased the dip temperatures by approximately 8.8% compared to the control heater. In conclusion, lauric acid storage can be used to stabilize the water temperature during the day time, while the myristic acid storage unit can be used as a thermal barrier against heat loss during the night time because of its relatively high melting temperature and low heat conduction coefficient in its solid phase. The experimental results have also indicated that the thermal characteristics of the PCM and the configuration of the PCM storage

  7. Variations in breastfeeding rates for very preterm infants between regions and neonatal units in Europe

    DEFF Research Database (Denmark)

    Bonet, Mercedes; Blondel, Béatrice; Agostino, Rocco

    2011-01-01

    To compare breastfeeding rates at discharge for very preterm infants between European regions and neonatal units, and to identify characteristics associated with breast feeding using multilevel models....

  8. Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

    Directory of Open Access Journals (Sweden)

    Xu Ji

    2015-01-01

    Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

  9. Evaluation of radiofrequency dielectric heaters workers exposure.

    Science.gov (United States)

    Benes, M; Del Frate, S; Villalta, R

    2008-01-01

    Radiofrequency dielectric heaters (RFDH) are widely used in the woodworking industry for gluing laminates by applying pressure and RF heating. The workers operating such equipment remain in the vicinity of the machinery all day and can therefore be exposed to considerable levels of electric and magnetic field at RFs. This work describes the method used to measure the strength of fields generated by this particular machinery. This procedure is based on current methods cited in the literature and introduces the necessary modifications to meet this specific case. In particular, as there is often a scarcity of technical data available relating to such heaters, it is suggested that a spectrum analyser be used for measurements in the frequencies domain. On the basis of the data obtained the norms of reference are established, the instrumentation to be used in successive stages determined as well as the identification of possible sources of interference from spurious signals. Furthermore, a mapping of the field strengths is presented and the means of determining the decay curve as a function of distance. This last type of measurement is done to estimate the effectiveness of grounding the machinery. The report ends with an estimate of the exposure of workers to electromagnetic fields and also some recommendations for reducing risk.

  10. Biogas Digester with Simple Solar Heater

    Directory of Open Access Journals (Sweden)

    Kh S Karimov

    2012-10-01

    Full Text Available ABSTRACT: In this research work, the design, fabrication and investigation of a biogas digester with simple solar heater are presented. For the solar heater, a built-in reverse absorber type heater was used. The maximum temperature (50°C inside the methane tank was taken as a main parameter for the design of the digester. Then, the energy balance equation for the case of a static mass of fluid being heated was used to model the process. The parameters of thermal insulation of the methane tank were also included in the calculations. The biogas digester consisted of a methane tank with built-in solar reverse absorber heater to harness the radiant solar energy for heating the slurry comprising of different organic wastes (dung, sewage, food wastes etc.. The methane tank was initially filled to 70% of its volume with organic wastes from the GIK institute’s sewage. The remaining volume was filled with sewage and cow dung from other sources. During a three month period (October-December, 2009 and another two month period (February-March, 2010, the digester was investigated. The effects of solar radiation on the absorber, the slurry’s temperature, and the ambient temperature were all measured during these investigations. It was found that using sewage only and sewage with cow dung in the slurry resulted in retention times of four and two weeks, respectively. The corresponding biogas produced was 0.4 m3 and 8.0 m3, respectively. Finally, this paper also elaborates on the upgradation of biogas through the removal of carbon dioxide, hydrogen sulphide and water vapour, and also the process of conversion of biogas energy into electric powerABSTRAK: Kajian ini membentangkan rekabentuk, fabrikasi dan penyelidikan tentang pencerna biogas dengan pemanas solar ringkas. Sebagai pemanas solar, ia dilengkapkan dengan penyerap pemanas beralik. Suhu maksimum(50oC di dalam tangki metana telah diambil sebagai parameter utama rekabentuk pencerna. Dengan menggunakan

  11. Experimental Investigation of a Natural Circulation Solar Domestic Water Heater Performance under Standard Consumption Rate

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Taherian, H.; Ganji, D. D.

    2012-01-01

    This paper reports experimental studies on the performance of a natural circulation solar water heater considering the weather condition of a city in north of Iran. The tests are done on clear and partly cloudy days. The variations of storage tank temperature due to consumption from the tank, daily...... consumption influence on the solar water heater efficiency, and on the input temperature of the collector are studied and the delivered daily useful energy has been obtained. The results show that by withdrawing from storage tank, the system as well as its collector efficiency will increase. Considering...... the value of the coefficient FRUL and τα, which are obtained experimentally as 6.03 and 0.83 respectively, average. monthly total load that is covered by this solar water heating system is estimated....

  12. Parametric excitation of whistler waves by HF heater

    Science.gov (United States)

    Kuo, S. P.; Lee, M. C.

    1989-01-01

    Possible generation of whistler waves by Tromso HF heater is investigated. It is shown that the HF heater wave can parametrically decay into a whistler wave and a Langmuir wave. Since whistler waves may have a broad range of frequency, the simultaneously excited Langmuir waves can have a much broader frequency bandwidth than those excited by the parametric decay instability.

  13. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion...

  14. Intra- and inter-unit variation in fly ash petrography and mercury adsorption: Examples from a western Kentucky power station

    Science.gov (United States)

    Hower, J.C.; Finkelman, R.B.; Rathbone, R.F.; Goodman, J.

    2000-01-01

    Fly ash was collected from eight mechanical and 10 baghouse hoppers at each of the twin 150-MW wall-fired units in a western Kentucky power station. The fuel burned at that time was a blend of many low-sulfur, high-volatile bituminous Central Appalachian coals. The baghouse ash showed less variation between units than the mechanical hoppers. The mechanical fly ash, coarser than the baghouse ash, showed significant differences in the amount of total carbon and in the ratio of isotropic coke to both total carbon and total coke - the latter excluding inertinite and other unburned, uncoked coal. There was no significant variation in proportions of inorganic fly ash constituents. The inter-unit differences in the amount and forms of mechanical fly ash carbon appear to be related to differences in pulverizer efficiency, leading to greater amounts of coarse coal, therefore unburned carbon, in one of the units. Mercury capture is a function of both the total carbon content and the gas temperature at the point of fly ash separation, mercury content increasing with an increase in carbon for a specific collection system. Mercury adsorption on fly ash carbon increases at lower flue-gas temperatures. Baghouse fly ash, collected at a lower temperature than the higher-carbon mechanically separated fly ash, contains a significantly greater amount of Hg.

  15. Infrared transparent graphene heater for silicon photonic integrated circuits.

    Science.gov (United States)

    Schall, Daniel; Mohsin, Muhammad; Sagade, Abhay A; Otto, Martin; Chmielak, Bartos; Suckow, Stephan; Giesecke, Anna Lena; Neumaier, Daniel; Kurz, Heinrich

    2016-04-18

    Thermo-optical tuning of the refractive index is one of the pivotal operations performed in integrated silicon photonic circuits for thermal stabilization, compensation of fabrication tolerances, and implementation of photonic operations. Currently, heaters based on metal wires provide the temperature control in the silicon waveguide. The strong interaction of metal and light, however, necessitates a certain gap between the heater and the photonic structure to avoid significant transmission loss. Here we present a graphene heater that overcomes this constraint and enables an energy efficient tuning of the refractive index. We achieve a tuning power as low as 22 mW per free spectral range and fast response time of 3 µs, outperforming metal based waveguide heaters. Simulations support the experimental results and suggest that for graphene heaters the spacing to the silicon can be further reduced yielding the best possible energy efficiency and operation speed.

  16. Toxic organic pollutants from kerosene space heaters in Iran.

    Science.gov (United States)

    Keyanpour-Rad, Mansoor

    2004-03-01

    The aim of this study was to investigate qualitatively the emission of toxic organic pollutants from an unventilated conventional kerosene space heater commonly used in Iran. A brand new common convective kerosene space heater, the "Aladdin," was used for this study. The well-tuned convective heater was operated in a 2.6-m(3) test chamber and then the emission was tested for organic pollutants. The emission was collected on Teflon-impregnated glass-fiber filters and XAD-2 resin and then analyzed by gas chromatography-mass spectroscopy. It was found that in addition to the ordinary pollutant gases, the heater emits aliphatic hydrocarbons, alcohols, polyaromatic hydrocarbons and the related nitrated compounds, phthalates, naphthalenes, and some other toxic organic compounds. However, it was found that the heater did not emit fluoranthene, cyclohexane, benzoic acid, and higher-molecular-weight alkylbenzenes, which could have resulted from the combustion of some other types of kerosene.

  17. Note: Improved heater design for high-temperature hollow cathodes

    Science.gov (United States)

    McDonald, M. S.; Gallimore, A. D.; Goebel, D. M.

    2017-02-01

    We present an improved heater design for thermionic cathodes using a rhenium filament encased in a boron nitride ceramic sleeve. This heater is relatively simple to fabricate, yet has been successfully used to reliably and repeatably light a lanthanum hexaboride (LaB6) hollow cathode based on a previously published design without noticeable filament degradation over hundreds of hours of operation. The high decomposition temperature of boron nitride (2800 C for inert environments) and melting point for rhenium (3180 C) make this heater especially attractive for use with LaB6, which may require operating temperatures upwards of 1700 C. While boron nitride decomposes in air above 1000 C, the heater was used only at vacuum with an inert gas discharge, and no degradation was observed. Limitations of current state of the art cathode heaters are also discussed and compared with the rhenium-boron nitride combination.

  18. Evolution of morphological integration. I. Functional units channel stress-induced variation in shrew mandibles.

    Science.gov (United States)

    Badyaev, Alexander V; Foresman, Kerry R

    2004-06-01

    Stress-induced deviations from normal development are often assumed to be random, yet their accumulation and expression can be influenced by patterns of morphological integration within an organism. We studied within-individual developmental variation (fluctuating asymmetry) in the mandible of four shrew species raised under normal and extreme environments. Patterns of among-individual variation and fluctuating asymmetry were strongly concordant in traits that were involved in the attachment of the same muscles (i.e., functionally integrated traits), and fluctuating asymmetry was closely integrated among these traits, implying direct developmental interactions among traits involved in the same function. Stress-induced variation was largely confined to the directions delimited by functionally integrated groups of traits in the pattern that was concordant with species divergence--species differed most in the same traits that were most sensitive to stress within each species. These results reveal a strong effect of functional complexes on directing and incorporating stress-induced variation during development and might explain the historical persistence of sets of traits involved in the same function in shrew jaws despite their high sensitivity to environmental variation.

  19. Heat Pump Water Heater Technology Assessment Based on Laboratory Research and Energy Simulation Models: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hudon, K.; Sparn, B.; Christensen, D.; Maguire, J.

    2012-02-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. Laboratory results demonstrate the efficiency of this technology under most of the conditions tested and show that differences in control schemes and design features impact the performance of the individual units. These results were used to understand current model limitations, and then to bracket the energy savings potential for HPWH technology in various US climate regions. Simulation results show that HPWHs are expected to provide significant energy savings in many climate zones when compared to other types of water heaters (up to 64%, including impact on HVAC systems).

  20. Electric tubing heater improves well production in CO[sub 2] flood

    Energy Technology Data Exchange (ETDEWEB)

    Baud, W. (Shell Western E and P, Houston, TX (United States)); Eastlund, B. (Production Technologies International Inc., Houston, TX (United States))

    1994-04-18

    Installation of a downhole heater in a well eliminated production interruption caused by downhole paraffin and hydrate buildup, exacerbated by cooling effects of CO[sub 2]. The well is one of 20 operated by Shell Western E and P Inc. in the CO[sub 2]-flooded portion of the South Crossett Devonian Unit (SCDU) in the Permian basin of West Texas. Prior to heater installation, the well's production routinely choked off in 2 days unless the downhole impairment was mechanically removed. Mechanical cutting established that the paraffin and hydrate buildup was in the upper 2,000 ft of the 5,300-ft well. The fluid exit temperature, depending on the choke setting, fluctuated between 14 and 30 F. The paper describes the unsuccessful results from conventional treatments, and the new method.

  1. Perancangan Sistem Pemantauan Pengendali Suhu pada Stirred Tank Heater menggunakan Supervisory Control and Data Acquisition (SCADA

    Directory of Open Access Journals (Sweden)

    Ike Bayusari

    2013-04-01

    Full Text Available This paper discusses design of a suhue control monitoring system in stirred tank heater system that has an important function in industrial processes. Monitoring of suhue control system in stirred tank heater is designed using Supervisory Control and Data Acquisition (SCADA that control function of industrial processes. While the actuator to be controlled is the position of burner openings, so that the heat can be adjusted to meet a predetermined set-point. The suhue controller that is also used as a Remote Terminal Unit (RTU is Programmable Logic Controller (PLC. The testing result showed on SCADA system was quite good, where the average percentage of deviation for testing of set-point data was 0.76687%, and the percentage of deviation for testing of suhue data was 0.082%.

  2. Variation exists in rates of admission to intensive care units for heart failure patients across hospitals in the United States

    Science.gov (United States)

    Safavi, Kyan C.; Dharmarajan, Kumar; Kim, Nancy; Strait, Kelly M.; Li, Shu-Xia; Chen, Serene I.; Lagu, Tara; Krumholz, Harlan M.

    2013-01-01

    Background Despite increasing attention on reducing relatively costly hospital practices while maintaining the quality of care, few studies have examined how hospitals use the intensive care unit (ICU), a high-cost setting, for patients admitted with heart failure (HF). We characterized hospital patterns of ICU admission for patients with HF and determined their association with the use of ICU-level therapies and patient outcomes. Methods and Results We identified 166,224 HF discharges from 341 hospitals in the 2009–10 Premier Perspective® database. We excluded hospitals with transfers. We defined ICU as including medical ICU, coronary ICU, and surgical ICU. We calculated the percent of patients admitted directly to an ICU. We compared hospitals in the top-quartile (high ICU admission) with the remaining quartiles. The median percentage of ICU admission was 10% (Interquartile Range 6% to 16%; range 0% to 88%). In top-quartile hospitals, treatments requiring an ICU were used less often: percentage of ICU days receiving mechanical ventilation (6% top quartile versus 15% others), non-invasive positive pressure ventilation (8% versus 19%), vasopressors and/or inotropes (9% versus 16%), vasodilators (6% versus 12%), and any of these interventions (26% versus 51%). Overall HF in-hospital risk standardized mortality was similar (3.4% versus 3.5%; P = 0.2). Conclusions ICU admission rates for HF varied markedly across hospitals and lacked association with in-hospital risk-standardized mortality. Greater ICU use correlated with fewer patients receiving ICU interventions. Judicious ICU use could reduce resource consumption without diminishing patient outcomes. PMID:23355624

  3. Temporal variation in United States firearm injuries 1993-2008: results from a national data base

    Directory of Open Access Journals (Sweden)

    Randall T. Loder

    2014-01-01

    Full Text Available Abstract: Background: There are few studies that address temporal variation in firearm associated injuries. It was the purpose of this study to analyze the temporal variation in the types and patterns of injuries associated with firearm use from a national data base. Methods: The database used was the Inter-University Consortium for Political and Social Research Firearm Injury Surveillance Study 1993-2008. Emergency department visits associated with firearm use were analyzed for month and day of the week for various demographic variables. Statistical analyses were performed using SUDAAN 10™ software to give national estimates. Temporal variation by month or day was assessed using histograms, circular distributions, and cosinor analyses. Variation by month and day combined were analyzed using three dimensional contours. Results: There were an estimated 1,841,269 injuries. Circular analyses demonstrated a non-uniform distribution for all parameters for both month and day of injury (p less than 0.001. The overall peak was September 15 with several exceptions. Injuries from BB guns had a peak on May 22, a diagnosis of a foreign body on July 11, and patients aged 10 to 14 years on April 9.The peak day was always Saturday/Sunday when significant variation existed. There were many different patterns for month and day combined. Some were “a rapidly rising high mountain starting at sea level” (hunting, or others a “series of mountain ranges starting from a high plain or steppe” (hospital admissions. Conclusions: This study provides altogether new information regarding temporal variation for injuries associated with firearms in the USA. These results can be used to assist medical resource allocation and prevention campaigns. Education campaigns can be emphasized before the peaks for which prevention is desired (eg. BB gun prevention campaigns should be concentrated in March, prior to the April/May peak.

  4. Integrity Assessment of GOH Heater Tube

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Hong, J. H.; Oh, Y. J.; Yoon, J. H.; Oh, J. M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-08-01

    An assessment of structural integrity of ASTM A312-TP347 GOH heater tube was performed. The surface notches which had been produced during tube manufacturing process were analyzed microscopically. Chemical analysis, hardness tests, tensile tests, and J-Integral fracture resistance tests were carried out to compare the mechanical properties with those of the material specification and also with the other material of the same type. The test results showed the mechanical properties of the GOH tube material are within the specification range. An elastic-plastic fracture mechanics analysis based on the DPFAD method reveals the tube an appropriate safety margin for the normal operation. 13 refs., 5 tabs., 24 figs. (author)

  5. Variation in chlorophyll content per unit leaf area in spring wheat and implications for selection in segregating material.

    Directory of Open Access Journals (Sweden)

    John Hamblin

    Full Text Available Reduced levels of leaf chlorophyll content per unit leaf area in crops may be of advantage in the search for higher yields. Possible reasons include better light distribution in the crop canopy and less photochemical damage to leaves absorbing more light energy than required for maximum photosynthesis. Reduced chlorophyll may also reduce the heat load at the top of canopy, reducing water requirements to cool leaves. Chloroplasts are nutrient rich and reducing their number may increase available nutrients for growth and development. To determine whether this hypothesis has any validity in spring wheat requires an understanding of genotypic differences in leaf chlorophyll content per unit area in diverse germplasm. This was measured with a SPAD 502 as SPAD units. The study was conducted in series of environments involving up to 28 genotypes, mainly spring wheat. In general, substantial and repeatable genotypic variation was observed. Consistent SPAD readings were recorded for different sampling positions on leaves, between different leaves on single plant, between different plants of the same genotype, and between different genotypes grown in the same or different environments. Plant nutrition affected SPAD units in nutrient poor environments. Wheat genotypes DBW 10 and Transfer were identified as having consistent and contrasting high and low average SPAD readings of 52 and 32 units, respectively, and a methodology to allow selection in segregating populations has been developed.

  6. Thermal emission of neutron stars with internal heaters

    CERN Document Server

    Kaminker, A D; Potekhin, A Y; Yakovlev, D G

    2014-01-01

    Using 1D and 2D cooling codes we study thermal emission from neutron stars with steady state internal heaters of various intensities and geometries (blobs or spherical layers) located at different depths in the crust. The generated heat tends to propagate radially, from the heater down to the stellar core and up to the surface; it is also emitted by neutrinos. In local regions near the heater the results are well described with the 1D code. The heater's region projects onto the stellar surface forming a hot spot. There are two heat propagation regimes. In the first, conduction outflow regime (realized at heat rates $H_0 \\lesssim 10^{20}$ erg cm$^{-3}$ s$^{-1}$ or temperatures $T_\\mathrm{h} \\lesssim 10^9$ K in the heater) the thermal surface emission of the star depends on the heater's power and neutrino emission in the stellar core. In the second, neutrino outflow regime ($H_0 \\gtrsim 10^{20}$ erg cm$^{-3}$ s$^{-1}$ or $T_\\mathrm{h} \\gtrsim 10^9$ K) the surface thermal emission becomes independent of heater's...

  7. Internal Variations in Health-care Federalism in Canada and the United States

    Directory of Open Access Journals (Sweden)

    Vandna Bhatia

    2014-12-01

    Full Text Available Federal systems are prone to dividing health benefits inconsistently across subnational jurisdictions. In this article, we examine how federalism intersects with economic and social factors, particularly gender and immigration status, to create structural barriers to accessing and receiving necessary healthcare. Drawing on insights from the historical institutionalist literature and the experiences of immigrant women in the Canadian and American health systems, we find significant subnational variations in access to health services and insurance coverage. Gaps in service – which are filled (if at all by costly, inaccessible private provision – are the product of piecemeal policymaking, as new programs and services are layered onto existing systems which are themselves outdated and anachronistic. Our analysis demonstrates the need to move beyond analyses of federal state architectures to an intersectional approach to better understand the differential negative impact of subnational variations on equity between social groups and their ability to access to basic health services.

  8. The Reproductive Context of Cohabitation in the United States: Recent Change and Variation in Contraceptive Use

    Science.gov (United States)

    Sweeney, Megan M.

    2010-01-01

    Drawing on data from 2 waves of the National Survey of Family Growth (N = 11,065), the current research addressed 2 overarching questions about the reproductive context of cohabitation in the United States. First, did patterns of contraceptive use among cohabitors change during the last 2 decades of the 20th century? Second, did patterns of…

  9. Quantifying variation in forest disturbance, and its effects on aboveground biomass dynamics, across the eastern United States.

    Science.gov (United States)

    Vanderwel, Mark C; Coomes, David A; Purves, Drew W

    2013-05-01

    The role of tree mortality in the global carbon balance is complicated by strong spatial and temporal heterogeneity that arises from the stochastic nature of carbon loss through disturbance. Characterizing spatio-temporal variation in mortality (including disturbance) and its effects on forest and carbon dynamics is thus essential to understanding the current global forest carbon sink, and to predicting how it will change in future. We analyzed forest inventory data from the eastern United States to estimate plot-level variation in mortality (relative to a long-term background rate for individual trees) for nine distinct forest regions. Disturbances that produced at least a fourfold increase in tree mortality over an approximately 5 year interval were observed in 1-5% of plots in each forest region. The frequency of disturbance was lowest in the northeast, and increased southwards along the Atlantic and Gulf coasts as fire and hurricane disturbances became progressively more common. Across the central and northern parts of the region, natural disturbances appeared to reflect a diffuse combination of wind, insects, disease, and ice storms. By linking estimated covariation in tree growth and mortality over time with a data-constrained forest dynamics model, we simulated the implications of stochastic variation in mortality for long-term aboveground biomass changes across the eastern United States. A geographic gradient in disturbance frequency induced notable differences in biomass dynamics between the least- and most-disturbed regions, with variation in mortality causing the latter to undergo considerably stronger fluctuations in aboveground stand biomass over time. Moreover, regional simulations showed that a given long-term increase in mean mortality rates would support greater aboveground biomass when expressed through disturbance effects compared with background mortality, particularly for early-successional species. The effects of increased tree mortality on

  10. Substrate heater for the growth of epitaxial silicon films

    Science.gov (United States)

    Deming, Matthew; Varhue, Walter; Adams, Edward; Lavoie, Mark

    1999-03-01

    The single wafer processing of epitaxial Si films requires that special attention be paid to the design of the substrate heater assembly. This document describes the evolution and testing of an in situ heater used to deposit epitaxial Si films at temperatures as high as 700 °C. One problem encountered was the production of excessive levels of ultraviolet radiation which contributed to the desorption of water vapor from the vacuum chamber walls during the in situ cleaning process. A second problem involved the formation of a molybdenum containing film that poisoned epitaxial growth. A final proven in situ heater design is presented which avoids these problems.

  11. Design and Implementation of the MSL Cruise Propulsion Tank Heaters

    Science.gov (United States)

    Krylo, Robert; Mikhaylov, Rebecca; Cucullu, Gordon; Watkins, Brenda

    2008-01-01

    This slide presentation reviews the design and the implementation of the heaters for the Mars Science Laboratory (MSL). The pressurized tanks store hydrazine that freezes at 2 C, this means that heaters are required to keep the hydrazine and the helium at 36 C for the trip to Mars. Using the TMG software the heat loss was analyzed, and a thermal model simulates a half full tank which yielded a 13W heating requirement for each hemisphere. Views of the design, and the heater are included.

  12. Research and development of a heat-pump water heater. Volume 2. R and D task reports

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, R.L.; Amthor, F.R.; Doyle, E.J.

    1978-08-01

    The heat pump water heater is a device that works much like a window air conditioner except that heat from the home is pumped into a water tank rather than to the outdoors. The objective established for the device is to operate with a Coefficient of Performance (COP) of 3 or, an input of one unit of electric energy would create three units of heat energy in the form of hot water. With such a COP, the device would use only one-third the energy and at one-third the cost of a standard resistance water heater. This Volume 2 contains the final reports of the three major tasks performed in Phase I. In Task 2, a market study identifies the future market and selects an initial target market and channel of distribution, all based on an analysis of the parameters affecting feasibility of the device and the factors that will affect its market acceptance. In the Task 3 report, the results of a design and test program to arrive at final designs of heat pumps for both new water heaters and for retrofitting existing water heaters are presented. In the Task 4 report, a plan for an extensive field demonstration involving use in actual homes is presented. Volume 1 contains a final summary report of the information in Volume 2.

  13. 75 FR 52892 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2010-08-30

    ... discretion, this direct measurement procedure is optional for vented heaters without thermal stack dampers... efficiency is calculated for vented heaters with manual controls and thermal dampers. For all other vented... Procedures for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters AGENCY: Office of...

  14. 78 FR 2340 - Energy Conservation Program: Test Procedures for Residential Water Heaters and Commercial Water...

    Science.gov (United States)

    2013-01-11

    ... also questionable whether thermal efficiency is an appropriate metric for smaller storage water heaters... that the test procedure for residential water heaters utilized the thermal efficiency and standby loss..., particularly for heat pump water heaters and gas instantaneous water heaters. 3. Revised Thermal Efficiency...

  15. 75 FR 20111 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

    Science.gov (United States)

    2010-04-16

    ... 46,000 65 Table II.3--Current Federal Energy Conservation Standards for Pool Heaters Thermal efficiency as of Product class January 1, 1990 Gas-Fired Pool Heater Thermal Efficiency = 78% ] 2. History of... Heaters, Direct Heating Equipment, and Pool Heaters; Final Rule #0;#0;Federal Register / Vol. 75, No....

  16. 76 FR 56347 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2011-09-13

    ... of the pool heater as: E OUT = BOH Where: BOH = as defined in 5.2 of this appendix E t = thermal... defined in 5.3 of this appendix 5.4.3 Calculate the pool heater integrated thermal efficiency (TE I ) (in... Residential Water Heaters, Direct Heating Equipment, and Pool Heaters (Standby Mode and Off Mode)...

  17. Modeling heat transfer from quench protection heaters to superconducting cables in Nb3Sn magnets

    CERN Document Server

    Salmi, T; Caspi, S; Felice, H; Prestemon, S; Chlachidze, G; Kate, H H J ten

    2013-01-01

    We use a recently developed quench protection heater modeling tool for an analysis of heater delays in superconducting high-field Nb3Sn accelerator magnets. The results suggest that the calculated delays are consistent with experimental data, and show how the heater delay depends on the main heater design parameters.

  18. 40 CFR 279.23 - On-site burning in space heaters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

  19. Variation in the interservice intervals of dairy cows in the United Kingdom.

    Science.gov (United States)

    Remnant, J G; Green, M J; Huxley, J N; Hudson, C D

    2015-02-01

    An understanding of the normal estrous-cycle length of the cow is important when managing and monitoring dairy-herd fertility. Although the normal interovulatory interval is widely considered to be 21 d, some studies have found alternative intervals to be more prevalent; previously, most of the variation in interval length was expected to be between cows. The aim of this study was to assess the time between inseminations (interservice interval, ISI) in a large number of dairy cows and to explore possible associations between cow factors and estrous-cycle length. The study used ISI data from 42,252 cows in 159 herds across England and Wales. Univariate analysis of the subset of 114,572 intervals between 15 and 30 d (a range covering the increased frequency of ISI occurring at the expected time of the first return to estrus) following an insemination revealed a modal ISI of 22d. Primiparous heifers had a modal ISI of 21 d. Significant differences existed between the distribution of ISI for different yield groups, parity numbers, and the number of inseminations. Multilevel regression modeling was used to evaluate the associations between cow factors and ISI, while accounting for clustering at the herd and cow level. This revealed significant associations between predicted ISI and insemination number, days in milk, lactation 305-d milk yield, and month and year of insemination. Variance partition coefficients indicated that only 1% of variation in ISI was at the herd level, 12% at the animal level, and 87% at the insemination level, indicating that cycle length varies substantially more between cycles within a cow than between cows or herds. These findings suggest the normal range of ISI for modern UK dairy cows is longer than expected and cycle length has a large amount of unexplained variation within individual animals over time.

  20. Geographic region and racial variations in polypharmacy in the United States.

    Science.gov (United States)

    Cashion, Winn; McClellan, William; Howard, George; Goyal, Abhinav; Kleinbaum, David; Goodman, Michael; Prince, Valerie; Muntner, Paul; McClure, Leslie A; McClellan, Ann; Judd, Suzanne

    2015-06-01

    Medications can have unintended effects. High medication use populations may benefit from increased regimen oversight. Limited knowledge exists concerning racial and regional polypharmacy variation. We estimated total medication distributions (excluding supplements) of American black and white adults and assessed racial and regional polypharmacy variation. REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort data (n = 30,239 U.S. blacks and whites aged ≥45 years) were analyzed. Home pill bottle inspections assessed the last two weeks' medications. Polypharmacy (≥8 medications) was determined by summing prescription and/or over-the-counter ingredients. Population-weighted logistic regression assessed polypharmacy's association with census region, race, and sex. The mean ingredient number was 4.12 (standard error = 0.039), with 15.7% of REGARDS using 8 ingredients or more. In crude comparisons, women used more medications than men, and blacks and whites reported similar mean ingredients. A cross-sectional, logistic model adjusting for demographics, socioeconomics, and comorbidities showed increased polypharmacy prevalence in whites versus blacks (OR [95% CI]: 0.63, [0.55-0.72]), women (1.94 [1.68-2.23]), and Southerners (broadly Southeasterners and Texans; 1.48 [1.17-1.87]) versus Northeasterners (broadly New England and upper Mid-Atlantic). Possible limitations include polypharmacy misclassification and model misspecification. Polypharmacy is common. Race and geography are associated with polypharmacy variation. Further study of underlying factors explaining these differences is warranted. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Measure Guideline: Heat Pump Water Heaters in New and Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Puttagunta, S.; Owens, D.

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Heat pump water heaters (HPWHs) promise to significantly reduce energy consumption for domestic hot water (DHW) over standard electric resistance water heaters (ERWHs). While ERWHs perform with energy factors (EFs) around 0.9, new HPWHs boast EFs upwards of 2.0. High energy factors in HPWHs are achieved by combining a vapor compression system, which extracts heat from the surrounding air at high efficiencies, with electric resistance element(s), which are better suited to meet large hot water demands. Swapping ERWHs with HPWHs could result in roughly 50% reduction in water heating energy consumption for 35.6% of all U.S. households. This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. While HPWHs promise to significantly reduce energy use for DHW, proper installation, selection, and maintenance of HPWHs is required to ensure high operating efficiency and reliability. This document is intended to explore the issues surrounding HPWHs to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Section 1 of this guideline provides a brief description of HPWHs and their operation. Section 2 highlights the cost and energy savings of HPWHs as well as the variables that affect HPWH performance, reliability, and efficiency. Section 3 gives guidelines for proper installation and maintenance of HPWHs, selection criteria for locating HPWHs, and highlights of important differences between ERWH and HPWH installations. Throughout this document, CARB has included results from the evaluation of 14 heat pump water heaters (including three recently released HPWH

  2. Analytical Model for Ring Heater Thermal Compensation in Advanced LIGO

    CERN Document Server

    Ramette, Joshua; Brooks, Aidan; Blair, Carl; Wang, Haoyu; Heintze, Matthew

    2015-01-01

    Advanced laser interferometer gravitational-wave detectors use high laser power to achieve design sensitivity. A small part of this power is absorbed in the interferometer cavity mirrors where it creates thermal lenses, causing aberrations in the main laser beam that must be minimized by the actuation of "ring heaters," additional heater elements that are aimed to reduce the temperature gradients in the mirrors. In this article we derive the first analytical model of the temperature field generated by an ideal ring heater. We express the resulting optical aberration contribution to the main laser beam in this axisymmetric case. Used in conjunction with wavefront measurements, our model provides a more complete understanding of the thermal state of the cavity mirrors and will allow a more efficient use of the ring heaters in Advanced LIGO.

  3. ENERGY STAR Certified Water Heaters (V3.1)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Water Heaters that are effective April 16, 2015....

  4. A High Performance Cathode Heater for Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The current state-of-the-art co-axial swaged tantalum (Ta) heaters use magnesium oxide (MgO) insulators, which limits their operation to temperatures well below...

  5. New Home Buyer Solar Water Heater Trade-Off Study

    Energy Technology Data Exchange (ETDEWEB)

    Symmetrics Marketing Corporation

    1999-08-18

    This report details the results of a research conducted in 1998 and 1999 and outlines a marketing deployment plan designed for businesses interested in marketing solar water heaters in the new home industry.

  6. Quantifying Slope Effects and Variations in Crater Density across a Single Geologic Unit

    Science.gov (United States)

    Meyer, Heather; Mahanti, Prasun; Robinson, Mark; Povilaitis, Reinhold

    2016-10-01

    Steep underlying slopes (>~5°) significantly increase the rate of degradation of craters [1-3]. As a result, the density of craters is less on steeper slopes for terrains of the same age [2, 4]. Thus, when age-dating a planetary surface, an area encompassing one geologic unit of constant low slope is chosen. However, many key geologic units, such as ejecta blankets, lack sufficient area of constant slope to derive robust age estimates. Therefore, accurate age-dating of such units requires an accurate understanding of the effects of slope on age estimates. This work seeks to determine if the observed trend of decreasing crater density with increasing slopes [2] holds for craters >1 km and to quantify the effect of slope for craters of this size, focusing on the effect of slopes over the kilometer scale. Our study focuses on the continuous ejecta of Orientale basin, where we measure craters >1 km excluding secondaries that occur as chains or clusters. Age-dating via crater density measurements relies on uniform cratering across a single geologic unit. In the case of ejecta blankets and other impact related surfaces, this assumption may not hold due to the formation of auto- secondary craters. As such, we use LRO WAC mosaics [5], crater size-frequency distributions, absolute age estimates, a 3 km slope map derived from the WAC GLD100 [6], and density maps for various crater size ranges to look for evidence of non-uniform cratering across the continuous ejecta of Orientale and to determine the effect of slope on crater density. Preliminary results suggest that crater density does decrease with increasing slope for craters >1 km in diameter though at a slower rate than for smaller craters.References: [1] Trask N. J. and Rowan L. C. (1967) Science 158, 1529-1535. [2] Basilevsky (1976) Proc. Lunar Sci. Conf. 7th, p. 1005-1020. [3] Pohn and Offield (1970) USGS Prof. Pap., 153-162. [4] Xiao et al. (2013) Earth and Planet. Sci. Lett., 376, pgs. 1-11. doi:10.1016/j.epsl.2013

  7. Relation between soil-gas radon variation and different lithotectonic units, Garhwal Himalaya, India

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, Vinay M.; Bist, K.S.; Saini, N.K. [Wadia Institute of Himalayan Geology, Dehra Dun (India); Ramola, R.C. [Physics Department, H.N.B. Garhwal University campus, Tehri Garhwal (India)

    1999-11-01

    Measurements of radon concentration and uranium content in soil and rocks were made in the regions of the Alaknanda and Bhagirathi valleys in the Garhwal Himalaya by using radon emanometry and X-ray fluorescence method, respectively. The data were collected from different lithotectonic units along and across the various regional thrust planes, faults, shears, etc. The observed values were then correlated with the geological formations and structure of the area. Radon concentrations were found to be controlled by lithology, structure and associated uranium mineralization. A positive linear correlation was also observed between soil-gas radon and in situ uranium in the area.

  8. Temperature limited heater utilizing non-ferromagnetic conductor

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar,; Harold J. (Bellaire, TX), Harris; Kelvin, Christopher [Houston, TX

    2012-07-17

    A heater is described. The heater includes a ferromagnetic conductor and an electrical conductor electrically coupled to the ferromagnetic conductor. The ferromagnetic conductor is positioned relative to the electrical conductor such that an electromagnetic field produced by time-varying current flow in the ferromagnetic conductor confines a majority of the flow of the electrical current to the electrical conductor at temperatures below or near a selected temperature.

  9. Thermal performance of a new solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Tiris, C.; Ozbalta, N. [Ege Univ., Izmir (Turkey). Solar Energy Institute; Tiris, M.; Dincer, I. [TUBITAK-Marmara Research Center, Kocaeli (Turkey)

    1995-05-01

    A solar air heater, part of a food drying system using solar energy as a renewable energy source for heat, was developed and tested for several agricultural products (i.e., sultana grapes, green beans, sweet peppers, chili peppers). Drying processes were conducted in the chamber with forced natural air heated partly by solar energy. Solar air heater performances were discussed along with estimates of energy efficiency of the system. The obtained results indicate that the present system is efficiency and effective.

  10. Mathematical modeling of the area of tubular gas heater in the condensing mode of work

    OpenAIRE

    IRODOV V. F.; Bereziuk, G. G.

    2015-01-01

    Statement of the problem. Infrared tubular gas heaters are designed for burning gas, moving of the heated products of combustion with air inside the tubular heater and heating of the room where the heater is installed with the help of radiant and convective heat exchange with space of the room. Tubular gas heaters are simultaneously sources of heat supply and heating devices. Using of these heaters provides fuel economy and uniform distribution of comfortable heat. Maximum fuel economy can be...

  11. Effect of Fuel Wobbe Number on Pollutant Emissions from Advanced Technology Residential Water Heaters: Results of Controlled Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H.; Singer, Brett C.

    2014-03-01

    The research summarized in this report is part of a larger effort to evaluate the potential air quality impacts of using liquefied natural gas in California. A difference of potential importance between many liquefied natural gas blends and the natural gas blends that have been distributed in California in recent years is the higher Wobbe number of liquefied natural gas. Wobbe number is a measure of the energy delivery rate for appliances that use orifice- or pressure-based fuel metering. The effect of Wobbe number on pollutant emissions from residential water heaters was evaluated in controlled experiments. Experiments were conducted on eight storage water heaters, including five with “ultra low-NO{sub X}” burners, and four on-demand (tankless) water heaters, all of which featured ultra low-NO{sub X} burners. Pollutant emissions were quantified as air-free concentrations in the appliance flue and fuel-based emission factors in units of nanogram of pollutant emitter per joule of fuel energy consumed. Emissions were measured for carbon monoxide (CO), nitrogen oxides (NO{sub X}), nitrogen oxide (NO), formaldehyde and acetaldehyde as the water heaters were operated through defined operating cycles using fuels with varying Wobbe number. The reference fuel was Northern California line gas with Wobbe number ranging from 1344 to 1365. Test fuels had Wobbe numbers of 1360, 1390 and 1420. The most prominent finding was an increase in NO{sub X} emissions with increasing Wobbe number: all five of the ultra low-NO{sub X} storage water heaters and two of the four ultra low-NO{sub X} on-demand water heaters had statistically discernible (p<0.10) increases in NO{sub X} with fuel Wobbe number. The largest percentage increases occurred for the ultra low-NO{sub X} water heaters. There was a discernible change in CO emissions with Wobbe number for all four of the on-demand devices tested. The on-demand water heater with the highest CO emissions also had the largest CO increase

  12. Sensitivity to Madden-Julian Oscillation variations on heavy precipitation over the contiguous United States

    Science.gov (United States)

    Jones, Charles; Carvalho, Leila M. V.

    2014-10-01

    The Madden-Julian Oscillation (MJO) is the most prominent mode of tropical intraseasonal variability in the climate system and has worldwide influences on the occurrences and forecasts of heavy precipitation. This paper investigates the sensitivity of precipitation over the contiguous United States (CONUS) in a case study (boreal 2004-05 winter). Several major storms affected the western and eastern CONUS producing substantial economic and social impacts including loss of lives. The Weather Research and Forecasting (WRF) model is used to perform experiments to test the significance of the MJO amplitude. The control simulation uses the MJO amplitude observed by reanalysis, whereas the amplitude is modified in perturbation experiments. WRF realistically simulates the precipitation variability over the CONUS, although large biases occur over the Western and Midwest United States. Daily precipitation is aggregated in western, central and eastern sectors and the frequency distribution is analyzed. Increases in MJO amplitude produce moderate increases in the median and interquartile range and large and robust increases in extreme (90th and 95th percentiles) precipitation. The MJO amplitude clearly affects the transport of moisture from the tropical Pacific and Gulf of Mexico into North America providing moist rich air masses and the dynamical forcing that contributes to heavy precipitation.

  13. Geographic variation, genetic structure and conservation unit designation in the larch mountain salamander( Plethodon larselli)

    Science.gov (United States)

    Wagner, R.S.; Miller, Mark P.; Crisafulli, Charles; Haig, Susan M.

    2005-01-01

    The Larch Mountain salamander (Plethodon larselli Burns, 1954) is an endemic species in the Pacific northwestern United States facing threats related to habitat destruction. To facilitate development of conservation strategies, we used DNA sequences and RAPDs (random amplified polymorphic DNA) to examine differences among populations of this species. Phylogenetic analyses of cytochrome b revealed a clade of haplotypes from populations north of the Columbia River derived from a clade containing haplotypes from the river's southwestern region. Haplotypes from southeastern populations formed a separate clade. Nucleotide diversity was reduced in northern populations relative to southern populations. These results were corroborated by analyses of RAPD loci, which revealed similar patterns of clustering and diversity. Network analyses suggested that northern populations were colonized following a range expansion mediated by individuals from populations located southwest of the river. Changes in the Columbia River's location during the Pliocene and Pleistocene likely released distributional constraints on this species, permitting their northern range expansion. Based on the barrier presented by the Columbia River's present location and differences in haplotype diversity and population structure observed between northern and southern populations, we suggest that designation of separate management units encompassing each region may assist with mitigating different threats to this species.

  14. Gravity and Heater Size Effects on Pool Boiling Heat Transfer

    Science.gov (United States)

    Kim, Jungho; Raj, Rishi

    2014-01-01

    The current work is based on observations of boiling heat transfer over a continuous range of gravity levels between 0g to 1.8g and varying heater sizes with a fluorinert as the test liquid (FC-72/n-perfluorohexane). Variable gravity pool boiling heat transfer measurements over a wide range of gravity levels were made during parabolic flight campaigns as well as onboard the International Space Station. For large heaters and-or higher gravity conditions, buoyancy dominated boiling and heat transfer results were heater size independent. The power law coefficient for gravity in the heat transfer equation was found to be a function of wall temperature under these conditions. Under low gravity conditions and-or for smaller heaters, surface tension forces dominated and heat transfer results were heater size dependent. A pool boiling regime map differentiating buoyancy and surface tension dominated regimes was developed along with a unified framework that allowed for scaling of pool boiling over a wide range of gravity levels and heater sizes. The scaling laws developed in this study are expected to allow performance quantification of phase change based technologies under variable gravity environments eventually leading to their implementation in space based applications.

  15. Thermo-Electron Ballistic Coolers or Heaters

    Science.gov (United States)

    Choi, Sang H.

    2003-01-01

    Electronic heat-transfer devices of a proposed type would exploit some of the quantum-wire-like, pseudo-superconducting properties of single-wall carbon nanotubes or, optionally, room-temperature-superconducting polymers (RTSPs). The devices are denoted thermo-electron ballistic (TEB) coolers or heaters because one of the properties that they exploit is the totally or nearly ballistic (dissipation or scattering free) transport of electrons. This property is observed in RTSPs and carbon nanotubes that are free of material and geometric defects, except under conditions in which oscillatory electron motions become coupled with vibrations of the nanotubes. Another relevant property is the high number density of electrons passing through carbon nanotubes -- sufficient to sustain electron current densities as large as 100 MA/square cm. The combination of ballistic motion and large current density should make it possible for TEB devices to operate at low applied potentials while pumping heat at rates several orders of magnitude greater than those of thermoelectric devices. It may also enable them to operate with efficiency close to the Carnot limit. In addition, the proposed TEB devices are expected to operate over a wider temperature range

  16. Variation in cash price of the generic medications most prescribed by dermatologists in pharmacies across the United States.

    Science.gov (United States)

    Alghanem, Noor; Abokwidir, Manal; Fleischer, Alan B; Feldman, Steven R; Alghanem, Ward

    2017-03-01

    The United States has the highest drug costs in the world. Consumers complain about large price differences at pharmacies on generic drugs. To evaluate variation in cash prices of generic medications most prescribed in dermatology across different drugstores and states in United States. The 11 generic drugs most prescribed by dermatologists according to National Ambulatory Medical Care Survey were assessed. By using Google, the most common used pharmacies in United States were listed, which are located at a random selection of six states. By calling the first available number of each pharmacy in the six states and asking about the generic cash price of the smallest stock size and the most prescribed type, the data were collected. Drug prices varied; the median cumulative price of the 11 medications was highest at Rite Aid ($1226) and lowest at Walmart ($795.34) with 35% difference. The prices at CVS differed by 20% across different states; however, the prices at Walmart, Rite Aid and Walgreens were consistent. New York has the highest and Iowa the lowest prices, especially at CVS, ($1160.79) versus ($931.32). There are varieties in the prices for the generic medications in different pharmacies and States.

  17. Geographic variation in social acceptability of wildland fuels management in the western United States

    Science.gov (United States)

    Brunson, M.; Schindler, Bruce A.

    2004-01-01

    Contemporary natural resource management requires consideration of the social acceptability of management practices and conditions. Agencies wishing to measure, respond to, and influence social acceptability must understand the nuances of public perception regarding controversial issues. This study explores social acceptability judgments about one such issue: reduction of wildland fuel hazards on federal lands in the western United States. Citizens were surveyed in four locations where fire has been a significant ecological disturbance agent and public land agencies propose to reduce wildland fuel levels and wildfire hazards via prescribed burning, thinning, brush removal, and/or livestock grazing. Respondents in different locations differed in their knowledge about fire and fuel issues as well in their acceptability judgments. Differences are associated with location-specific social and environmental factors as well as individual beliefs. Results argue against using a??one-size-fits-alla?? policies or information strategies about fuels management.

  18. Understanding Variations of Soil Mapping Units and Associated Data for Forensic Science.

    Science.gov (United States)

    Suarez, Melissa D; Southard, Randal J; Parikh, Sanjai J

    2015-07-01

    Soil samples have potential to be useful in forensic investigations, but their utility may be limited due to the inherent variability of soil properties, the wide array of analytical methods, and complexity of data analysis. This study examined the differentiation of similar soils based on both gross (texture, color, mineralogy) and explicit soil properties (elemental composition, cation exchange, Fe-oxyhydroxides). Soils were collected from Fallbrook and adjacent map units from Riverside and San Diego Counties in California. Samples were characterized using multiple techniques, including chemical extracts, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy. Results were analyzed using multiple analytical approaches to compare counties and land uses. Some analyses (XRD, extractions) were better at distinguishing among samples than others (color, texture). Ratios of rare earth elements were particularly useful for distinguishing samples between counties. This potential to "fingerprint" soils illustrates the usefulness of a comprehensive soil database for criminal investigators.

  19. Spatial and temporal variation in microcystin occurrence in wadeable streams in the southeastern United States.

    Science.gov (United States)

    Loftin, Keith A; Clark, Jimmy M; Journey, Celeste A; Kolpin, Dana W; Van Metre, Peter C; Carlisle, Daren; Bradley, Paul M

    2016-09-01

    Despite historical observations of potential microcystin-producing cyanobacteria (including Leptolyngbya, Phormidium, Pseudoanabaena, and Anabaena species) in 74% of headwater streams in Alabama, Georgia, South Carolina, and North Carolina (USA) from 1993 to 2011, fluvial cyanotoxin occurrence has not been systematically assessed in the southeastern United States. To begin to address this data gap, a spatial reconnaissance of fluvial microcystin concentrations was conducted in 75 wadeable streams in the Piedmont region (southeastern USA) during June 2014. Microcystins were detected using enzyme-linked immunosorbent assay (limit = 0.10 µg/L) in 39% of the streams with mean, median, and maximum detected concentrations of 0.29 µg/L, 0.11 µg/L, and 3.2 µg/L, respectively. Significant (α = 0.05) correlations were observed between June 2014 microcystin concentrations and stream flow, total nitrogen to total phosphorus ratio, and water temperature; but each of these factors explained 38% or less of the variability in fluvial microcystins across the region. Temporal microcystin variability was assessed monthly through October 2014 in 5 of the streams where microcystins were observed in June and in 1 reference location; microcystins were repeatedly detected in all but the reference stream. Although microcystin concentrations in the present study did not exceed World Health Organization recreational guidance thresholds, their widespread occurrence demonstrates the need for further investigation of possible in-stream environmental health effects as well as potential impacts on downstream lakes and reservoirs. Environ Toxicol Chem 2016;35:2281-2287. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

  20. Epidemiological trends and geographic variation in hospital admissions for diverticulitis in the United States

    Institute of Scientific and Technical Information of China (English)

    Geoffrey C Nguyen; Justina Sam; Nitasha Anand

    2011-01-01

    AIM: To characterize the increasing incidence and geographic variation of acute diverticulitis. METHODS: Using the nationwide inpatient sample (NIS) we identified a cohort who had been admitted with diverticulitis between 1998 and 2005. We calculated age-, sex-, and region-specific rates of hospitalizations for diverticulitis over time. RESULTS: The age-adjusted hospitalization rate for diverticulitis increased from 61.8 per 100 000 to 75.5 per 100 000 between 1998 and 2005, and increased similarly in both sexes. Diverticulitis-associated admissions were male-predominant in those younger than age 45 years but were female-predominant thereafter. Admission rates increased the most among those < 45 years, while remaining unchanged for those ≥ 65 years. By 2005, the majority of hospitalized patients were < 65 years. Age-adjusted rates of diverticulitis-associated hospitalizations were lower in the West (50.4/100 000) compared to the Northeast (77.7/100 000), South (73.9/100 000), and Midwest (71.0/100 000). CONCLUSION: Diverticulitis-associated hospitalizations have steeply risen, especially in young adults. These epidemiological trends vary by geographic region and warrant further investigation into potential dietary and environmental etiologies.

  1. Water inflow into boreholes during the Stripa heater experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P.H.; Rachiele, R.; Remer, J.S.; Carlsson, H.

    1981-04-01

    During the operation of three in-situ heater experiments at Stripa, Sweden, groundwater flowed into many of the instrumentation and heater boreholes. These flows were recovered and measured routinely. The records of water inflow indicate two origins: inflow attributed to local hydrological pressure gradients, and water migration from cracks closing under the rapidly increasing, thermal-induced stress changes. The latter component appeared as a main pulse that occurred when the heaters were turned on, and lasted about 30 to 40 days, steadily declining over the next several months, and decreasing sharply when heater power was decreased or stopped. The magnitude of the total inflow per hole ranged over more than five decades, from 0.1 to over 10,000 liters over the 500 to 600 day time periods. When plotted against the logarithm of total volume, the frequency distribution displays a normal curve dependence with a mean of approximately 10 liters. Of this amount, 1 to 2 liters of flow into 38-mm-diam boreholes accompanied an increase in applied heat load. These amounts are compatible with rock porosities of a fraction of one percent. Inflow into the 3.6 and 5.0 kW heater holes peaked within 3 to 6 days after heater turn on, then declined to zero inflow, with no further inflow measured for the remainder of the experiments. In the heater holes of the time-scaled experiment, which operated at 1.125 kW or less, the initial pulse of inflow took much longer to decay, and 7 of 8 heater holes continued to flow throughout the experiment. The packing off and isolation of a borehole some 40 m distant in the ventilation drift dramatically increased the inflow into the heater holes in one of the three heater experiments. This demonstrated the existence of permeable flow paths among a number of boreholes. The records of water inflow demonstrate the need for a thorough understanding of the nature of fluid flow and storage in fractured crystalline rock.

  2. Ethnic Variations in Duodenal Villous Atrophy Consistent With Celiac Disease in the United States.

    Science.gov (United States)

    Krigel, Anna; Turner, Kevin O; Makharia, Govind K; Green, Peter H R; Genta, Robert M; Lebwohl, Benjamin

    2016-08-01

    Celiac disease is a common disorder with a worldwide distribution, although the prevalence among different ethnicities varies. We aimed to measure the prevalence of duodenal villous atrophy among patients of different ethnicities throughout the United States. We performed a cross-sectional study of all patients who had duodenal biopsies submitted to a national pathology laboratory between January 2, 2008 and April 30, 2015. The prevalence of villous atrophy was calculated for the following ethnicities by using a previously published algorithm based on patient names: North Indian, South Indian, East Asian, Hispanic, Middle Eastern, Jewish, and other Americans. Among all patients (n = 454,885), the median age was 53 years, and 66% were female. The overall prevalence of celiac disease was 1.74%. Compared with other Americans (n = 380,163; celiac disease prevalence, 1.83%), celiac disease prevalence was lower in patients of South Indian (n = 177, 0%; P = .08), East Asian (n = 4700, 0.15%; P ≤ .0001), and Hispanic (n = 31,491, 1.06%; P ≤ .0001) ethnicities. Celiac disease was more common in patients from the Punjab region (n = 617, 3.08%) than in patients from North India (n = 1195, 1.51%; P = .02). The prevalence of celiac disease among patients of Jewish (n = 17,806, 1.80%; P = .78) and Middle Eastern (n = 1903, 1.52%; P = .33) ethnicities was similar to that of other Americans. Among Jewish individuals (n = 17,806), the prevalence of celiac disease was 1.83% in Ashkenazi persons (n = 16,440) and 1.39% in Sephardic persons (n = 1366; P = .24). Among patients undergoing duodenal biopsy, individuals from the Punjab region of India constitute the ethnic group in the United States with the highest prevalence of villous atrophy consistent with celiac disease. Compared with other Americans, villous atrophy prevalence on duodenal biopsy is significantly lower among U.S. residents of South Indian, East Asian, and Hispanic ancestry. Copyright © 2016 AGA

  3. Pollution and regional variations of lung cancer mortality in the United States.

    Science.gov (United States)

    Moore, Justin Xavier; Akinyemiju, Tomi; Wang, Henry E

    2017-08-01

    The aims of this study were to identify counties in the United States (US) with high rates of lung cancer mortality, and to characterize the associated community-level factors while focusing on particulate-matter pollution. We performed a descriptive analysis of lung cancer deaths in the US from 2004 through 2014. We categorized counties as "clustered" or "non-clustered" - based on whether or not they had high lung cancer mortality rates - using novel geospatial autocorrelation methods. We contrasted community characteristics between cluster categories. We performed logistic regression for the association between cluster category and particulate-matter pollution. Among 362 counties (11.6%) categorized as clustered, the age-adjusted lung cancer mortality rate was 99.70 deaths per 100,000 persons (95%CI: 99.1-100.3). Compared with non-clustered counties, clustered counties were more likely in the south (72.9% versus 42.1%, Pobesity and physical inactivity, less access to healthcare, and greater unemployment rates (Plung mortality ranging from eastern Oklahoma through central Appalachia; these counties were characterized by higher pollution, a more rural population, lower socioeconomic status and poorer access to healthcare. To mitigate the burden of lung cancer mortality in the US, both urban and rural areas should consider minimizing air pollution. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Airborne observations of regional variation in fluorescent aerosol across the United States

    Science.gov (United States)

    Perring, A. E.; Schwarz, J. P.; Baumgardner, D.; Hernandez, M. T.; Spracklen, D. V.; Heald, C. L.; Gao, R. S.; Kok, G.; McMeeking, G. R.; McQuaid, J. B.; Fahey, D. W.

    2015-02-01

    Airborne observations of fluorescent aerosol were made aboard an airship during CloudLab, a series of flights that took place in September and October of 2013 and covered a wideband of longitude across the continental U.S. between Florida and California and between 28 and 37 N latitudes. Sampling occurred from near the surface to 1000 m above the ground. A Wideband Integrated Bioaerosol Sensor (WIBS-4) measured average concentrations of supermicron fluorescent particles aloft (1 µm to 10 µm), revealing number concentrations ranging from 2.1 ± 0.8 to 8.7 ± 2.2 × 104 particles m-3 and representing up to 24% of total supermicron particle number. We observed distinct variations in size distributions and fluorescent characteristics in different regions, and attribute these to geographically diverse bioaerosol. Fluorescent aerosol detected in the east is largely consistent with mold spores observed in a laboratory setting, while a shift to larger sizes associated with different fluorescent patterns is observed in the west. Fluorescent bioaerosol loadings in the desert west were as high as those near the Gulf of Mexico, suggesting that bioaerosol is a substantial component of supermicron aerosol both in humid and arid environments. The observations are compared to model fungal and bacterial loading predictions, and good agreement in both particle size and concentrations is observed in the east. In the west, the model underestimated observed concentrations by a factor between 2 and 4 and the prescribed particle sizes are smaller than the observed fluorescent aerosol. A classification scheme for use with WIBS data is also presented.

  5. Widespread distribution and unexpected variation among science faculty with education specialties (SFES) across the United States.

    Science.gov (United States)

    Bush, Seth D; Pelaez, Nancy J; Rudd, James A; Stevens, Michael T; Tanner, Kimberly D; Williams, Kathy S

    2013-04-30

    College and university science departments are increasingly taking an active role in improving science education. Perhaps as a result, a new type of specialized science faculty position within science departments is emerging--referred to here as science faculty with education specialties (SFES)--where individual scientists focus their professional efforts on strengthening undergraduate science education, improving kindergarten-through-12th grade science education, and conducting discipline-based education research. Numerous assertions, assumptions, and questions about SFES exist, yet no national studies have been published. Here, we present findings from a large-scale study of US SFES, who are widespread and increasing in numbers. Contrary to many assumptions, SFES were indeed found across the nation, across science disciplines, and, most notably, across primarily undergraduate, master of science-granting, and PhD-granting institutions. Data also reveal unexpected variations among SFES by institution type. Among respondents, SFES at master of science-granting institutions were almost twice as likely to have formal training in science education compared with other SFES. In addition, SFES at PhD-granting institutions were much more likely to have obtained science education funding. Surprisingly, formal training in science education provided no advantage in obtaining science education funding. Our findings show that the SFES phenomenon is likely more complex and diverse than anticipated, with differences being more evident across institution types than across science disciplines. These findings raise questions about the origins of differences among SFES and are useful to science departments interested in hiring SFES, scientific trainees preparing for SFES careers, and agencies awarding science education funding.

  6. Reliable, Economic, Efficient CO2 Heat Pump Water Heater for North America

    Energy Technology Data Exchange (ETDEWEB)

    Radcliff, Thomas D; Sienel, Tobias; Huff, Hans-Joachim; Thompson, Adrian; Sadegh, Payman; Olsommer, Benoit; Park, Young

    2006-12-31

    Adoption of heat pump water heating technology for commercial hot water could save up to 0.4 quads of energy and 5 million metric tons of CO2 production annually in North America, but industry perception is that this technology does not offer adequate performance or reliability and comes at too high of a cost. Development and demonstration of a CO2 heat pump water heater is proposed to reduce these barriers to adoption. Three major themes are addressed: market analysis to understand barriers to adoption, use of advanced reliability models to design optimum qualification test plans, and field testing of two phases of water heater prototypes. Market experts claim that beyond good performance, market adoption requires 'drop and forget' system reliability and a six month payback of first costs. Performance, reliability and cost targets are determined and reliability models are developed to evaluate the minimum testing required to meet reliability targets. Three phase 1 prototypes are designed and installed in the field. Based on results from these trials a product specification is developed and a second phase of five field trial units are built and installed. These eight units accumulate 11 unit-years of service including 15,650 hours and 25,242 cycles of compressor operation. Performance targets can be met. An availability of 60% is achieved and the capability to achieve >90% is demonstrated, but overall reliability is below target, with an average of 3.6 failures/unit-year on the phase 2 demonstration. Most reliability issues are shown to be common to new HVAC products, giving high confidence in mature product reliability, but the need for further work to minimize leaks and ensure reliability of the electronic expansion valve is clear. First cost is projected to be above target, leading to an expectation of 8-24 month payback when substituted for an electric water heater. Despite not meeting all targets, arguments are made that an industry leader could

  7. Comparative Study and Design of Solar Water Heater

    Directory of Open Access Journals (Sweden)

    K.Sainath,Y.krishna, Mohd Salahuddin, Mohammed Siddique Ahmed, Md Ismail, Syed Rahman,Mohammed Noman, Mohd Khaleel Ullah, Faraz Ur Rehman Azhar, Mohd Moizuddin,Mohd Riyaz Uddin.

    2014-10-01

    Full Text Available A solar water heater design is made from the plastic bottles of thumps up & plastic pipe(p.v.c run up by the centre of each solar heater in a row of bottles, these bottles act as glazing & hold reflectors made from the black paint. Solar water heaters are made of two basic parts: a solar collector that gathers radiant energy and a storage tank for the hot water inside. These systems are used to heat water for swimming pools, as well as for domestic cooking and cleaning needs. A system in which the sun’s heat is gathered by a solar collector and used to increase the temperature of a heat-transfer fluid , which flows through the pipes in the collector; the heat contained in this fluid then is conveyed and transferred to the water to be heated. Solar water heaters use the solar energy from the sun to generate heat (not electricity which can then be used to heat water for showering, space heating, industrial processes or even solar cooling. However, the research shows that the electric water spends about the 25% of its home energy costs on heating water. If we make a water heater without the collector then we can save a lot of money solar water heater do not polluted if one investing on SWH avoids carbon dioxide nitrogen oxide and sulphur dioxide and the other air pollution wastes and the utility generates power on your bum fuel to heat your household water when SWH replaces the an electric water heater. This electric displaced over 20 years replaced more than 50 tones avoided c02 emissions alone co2 traps heat in the upper most atmosphere thus, contributing to the ‘Green House Effect

  8. Genetic variation and exchange in Trypanosoma cruzi isolates from the United States.

    Directory of Open Access Journals (Sweden)

    Dawn M Roellig

    Full Text Available Trypanosoma cruzi, the causative agent of Chagas disease, is a multiclonal parasite with high levels of genetic diversity and broad host and geographic ranges. Molecular characterization of South American isolates of T. cruzi has demonstrated homologous recombination and nuclear hybridization, as well as the presence of 6 main genetic clusters or "discrete typing units" (DTUs. Few studies have extensively investigated such exchange events and genetic diversity in North American isolates. In the current study, we genetically characterized over 50 US isolates from wildlife reservoirs (e.g., raccoons, opossums, armadillos, skunks, domestic dogs, humans, nonhuman primates, and reduviid vectors from nine states (TX, CA, OK, SC, FL, GA, MD, LA, TN using a multilocus sequencing method. Single nucleotide polymorphisms were identified in sequences of the mismatch-repair class 2 (MSH2 and Tc52 genes. Typing based on the two genes often paralleled genotyping by classic methodologies using mini-exon and 18S and 24Sα rRNA genes. Evidence for genetic exchange was obtained by comparing sequence phylogenies of nuclear and mitochondrial gene targets, dihydrofolate reductase-thymidylate synthase (DHFR-TS and the cytochrome oxidase subunit II- NADH dehydrogenase subunit I region (COII-ND1, respectively. We observed genetic exchange in several US isolates as demonstrated by incongruent mitochondrial and nuclear genes phylogenies, which confirms a previous finding of a single genetic exchange event in a Florida isolate. The presence of SNPs and evidence of genetic exchange illustrates that strains from the US are genetically diverse, even though only two phylogenetic lineages have been identified in this region.

  9. Variation in Residential Care Community Nurse and Aide Staffing Levels: United States, 2014.

    Science.gov (United States)

    Rome, Vincent; Harris-Kojetin, Lauren D

    2016-02-19

    This report presents national and state estimates of staffing levels in residential care communities for registered nurses, licensed practical or vocational nurses, and aides in the United States for 2014. Data were drawn from the residential care community component of the 2014 wave of the biennial National Study of Long-Term Care Providers, conducted by the Centers for Disease Control and Prevention’s National Center for Health Statistics. For each staff type, the "staffing level" measure is presented as average hours per resident per day, defined as the total number of hours worked divided by the total number of residents, which does not necessarily reflect the amount of care given to a specific resident. Analyses examined the extent to which residential care community nurse and aide staffing levels varied by selected organizational characteristics and selected resident composition characteristics of the communities. Differences among subgroups were evaluated using two-sided t tests at the 0.05 level. In 2014, the total registered nurse, licensed practical or vocational nurse, and aide staffing level among all residential care communities was about 2 hours and 50 minutes. Registered nurse staffing levels differed for two of the three organizational characteristics (size and metropolitan statistical area [MSA]) and for only one of the four resident composition characteristics (primarily serving residents needing any assistance with activities of daily living). Licensed practical or vocational nurse staffing levels differed for all three organizational characteristics (size, MSA, and ownership) and for only one of the four resident composition characteristics (primarily serving residents diagnosed with Alzheimer’s disease or other dementias). In contrast, differences in aide staffing levels were common when examining both community organizational and resident composition characteristics. Registered nursing, licensed practical and vocational nursing, and aide

  10. Genetic variation and exchange in Trypanosoma cruzi isolates from the United States.

    Science.gov (United States)

    Roellig, Dawn M; Savage, Mason Y; Fujita, A Wendy; Barnabé, Christian; Tibayrenc, Michel; Steurer, Frank J; Yabsley, Michael J

    2013-01-01

    Trypanosoma cruzi, the causative agent of Chagas disease, is a multiclonal parasite with high levels of genetic diversity and broad host and geographic ranges. Molecular characterization of South American isolates of T. cruzi has demonstrated homologous recombination and nuclear hybridization, as well as the presence of 6 main genetic clusters or "discrete typing units" (DTUs). Few studies have extensively investigated such exchange events and genetic diversity in North American isolates. In the current study, we genetically characterized over 50 US isolates from wildlife reservoirs (e.g., raccoons, opossums, armadillos, skunks), domestic dogs, humans, nonhuman primates, and reduviid vectors from nine states (TX, CA, OK, SC, FL, GA, MD, LA, TN) using a multilocus sequencing method. Single nucleotide polymorphisms were identified in sequences of the mismatch-repair class 2 (MSH2) and Tc52 genes. Typing based on the two genes often paralleled genotyping by classic methodologies using mini-exon and 18S and 24Sα rRNA genes. Evidence for genetic exchange was obtained by comparing sequence phylogenies of nuclear and mitochondrial gene targets, dihydrofolate reductase-thymidylate synthase (DHFR-TS) and the cytochrome oxidase subunit II- NADH dehydrogenase subunit I region (COII-ND1), respectively. We observed genetic exchange in several US isolates as demonstrated by incongruent mitochondrial and nuclear genes phylogenies, which confirms a previous finding of a single genetic exchange event in a Florida isolate. The presence of SNPs and evidence of genetic exchange illustrates that strains from the US are genetically diverse, even though only two phylogenetic lineages have been identified in this region.

  11. Reviews on Rzewski’s Leftist Political Piano Variations: ‘The People United Will Never Be Defeated’

    Directory of Open Access Journals (Sweden)

    Deng Liang

    2017-02-01

    Full Text Available ‘The People United Will Never Be Defeated (1975 is an one-hour epic modern piano variations, is one with an exquisite structure as well as a humanistic content. As a political context, this could be a legendary piece as well, in its creation in Chile just before Pinochet's military regime and the music's subsequent meaning for so many leftist political enthusiasts. In his approach the author highlighted the role of music, i.e. the role of cultural power in crating consciousness and attracting masses of people to political causes inspiring them to fight for better future. In addition, the author opened a number of questions on performance of contemporary music on the basis of Rzewski’s own DVD recording, the analyzing of which revealed an interesting phenomenon because when Rzewski played his own music, his playing differentiated from his own score.

  12. A control approach for the operation of DG units under variations of interfacing impedance in grid-connected mode

    DEFF Research Database (Denmark)

    Hoseini, S. Kazem; Pouresmaeil, E.; Hosseinnia, S. H.

    2016-01-01

    converter is highly sensitive to the impacts of this impedance changes; then, DG unit cannot inject appropriate currents. To deal with the instability problem, a control method based on fractional order active sliding mode is proposed in this paper, which is less sensitive to variations of interfacing...... impedance. A fractional sliding surface, which demonstrates the desired dynamics of system is developed and then, the controller is designed in two phases as sliding and reaching phases to keep the control loop stable. Stability issues of the control method are discussed in details and the conditions...... in which the proposed model works in a stable operating mode is defined. The proposed control method takes a role to provide high quality power injection and ensures precise references tracking and fast response despite such uncertainties. Theoretical analyses and simulation results are established...

  13. On the variation of the Astronomical Unit and the corrections to planetary motion on an expanding locally anisotropic background

    CERN Document Server

    Ferreira, P Castelo

    2012-01-01

    In this work are computed analytical solutions for orbital motion on a background described by an Expanding Locally Anisotropic (ELA) metric ansatz. This metric interpolates between the Schwarzschild metric near the central mass and the Robertson-Walker metric describing the expanding cosmological background far from the central mass allowing for a fine-tuneable covariant parameterization of gravitational interactions corrections in between these two asymptotic limits. Assuming a non-varying gravitational constant, 'dG/dt=0', it is discussed the variation of the Astronomical Unit (AU) obtained from numerical analysis of the Solar System dynamics, being shown that the corrections to the orbital periods on the Solar System due to the decrease of the Sun's mass by radiation emission plus the General Relativity corrections due to the ELA metric background with respect to Schwarzschild backgrounds can be mapped to the reported yearly increase of the AU through the corrections to Kepler's third law. Based on the va...

  14. The 1997-98 El-Nino Event and Related Lightning Variations in the Southeastern United States

    Science.gov (United States)

    Buechler, D. E.; Goodman, S. J.; McCaul, E. W.; Knupp, K.

    1999-01-01

    The El Nino Southern Oscillation (ENSO) is a climate anomaly responsible for world-wide weather impacts ranging from droughts to floods. In the United States, warm episode years are known to produce above normal rainfall along the Southeast US Gulf Coast and into the Gulf of Mexico, with the greatest response observed in the October-March period of the current warm-episode year. The 1997-98 warm episode, notable for being the strongest event since 1982-83, presents our first opportunity to examine the response to a major ENSO event and determine the variation of wintertime thunderstorm activity in this part of the world. Due to the recent launch of a lightning sensor on NASA's Tropical Rainfall Measuring Mission (TRMM) in November 1997 and the expanded coverage of the National Lightning Detection Network (NLDN), we are able to examine such year-to-year changes in lightning activity with far greater detail than ever before.

  15. Hounsfield units variations. Impact on CT-density based conversion tables and their effects on dose distribution

    Energy Technology Data Exchange (ETDEWEB)

    Zurl, B.; Winkler, P.; Kapp, K.S. [University Medical School of Graz, Comprehensive Cancer Center Graz, Department of Therapeutic Radiotherapy and Oncology, Graz (Austria); Tiefling, R.; Kindl, P. [University of Technology, Institute of Materials Physics, Graz (Austria)

    2014-01-15

    Determination of dose error margins in radiation therapy planning due to variations in Hounsfield Units (HU) values dependent on the use of different CT scanning protocols. Based on a series of different CT scanning protocols used in clinical practice, conversion tables for radiation dose calculations were generated and subsequently tested on a phantom. These tables were then used to recalculate the radiation therapy plans of 28 real patients after an incorrect scanning protocol had inadvertently been used for these patients. Different CT parameter settings resulted in errors of HU values of up to 2.6 % for densities of < 1.1 g/cm{sup 3}, but up to 25.6 % for densities of > 1.1 g/cm{sup 3}. The largest errors were associated with changes in the tube voltage. Tests on a virtual water phantom with layers of variable thickness and density revealed a sawtooth-shaped curve for the increase of dose differences from 0.3 to 0.6 % and 1.5 % at layer thicknesses of 1, 3, and 7 cm, respectively. Use of a beam hardening filter resulted in a reference dose difference of 0.6 % in response to a density change of 5 %. The recalculation of data from 28 patients who received radiation therapy to the head revealed an overdose of 1.3 ± 0.4 % to the bone and 0.7 ± 0.1 % to brain tissue. On average, therefore, one monitor unit (range 0-3 MU) per 100 MU more than the correct dose had been given. Use of different CT scanning protocols leads to variations of up to 20 % in the HU values. This can result in a mean systematic dose error of 1.5 %. Specific conversion tables and automatic CT scanning protocol recognition could reduce dose errors of these types. (orig.)

  16. Racial/ethnic variations in substance-related disorders among adolescents in the United States.

    Science.gov (United States)

    Wu, Li-Tzy; Woody, George E; Yang, Chongming; Pan, Jeng-Jong; Blazer, Dan G

    2011-11-01

    While young racial/ethnic groups are the fastest growing population in the United States, data about substance-related disorders among adolescents of various racial/ethnic backgrounds are lacking. To examine the magnitude of past-year DSM-IV substance-related disorders (alcohol, marijuana, cocaine, inhalants, hallucinogens, heroin, analgesic opioids, stimulants, sedatives, and tranquilizers) among adolescents of white, Hispanic, African American, Native American, Asian or Pacific Islander, and multiple race/ethnicity. The 2005 to 2008 National Survey on Drug Use and Health. Academic research. Noninstitutionalized household adolescents aged 12 to 17 years. Substance-related disorders were assessed by standardized survey questions administered using the audio computer-assisted self-interviewing method. Of 72 561 adolescents aged 12 to 17 years, 37.0% used alcohol or drugs in the past year; 7.9% met criteria for a substance-related disorder, with Native Americans having the highest prevalence of use (47.5%) and disorder (15.0%). Analgesic opioids were the second most commonly used illegal drugs, following marijuana, in all racial/ethnic groups; analgesic opioid use was comparatively prevalent among adolescents of Native American (9.7%) and multiple race/ethnicity (8.8%). Among 27 705 past-year alcohol or drug users, Native Americans (31.5%), adolescents of multiple race/ethnicity (25.2%), adolescents of white race/ethnicity (22.9%), and Hispanics (21.0%) had the highest rates of substance-related disorders. Adolescents used marijuana more frequently than alcohol or other drugs, and 25.9% of marijuana users met criteria for marijuana abuse or dependence. After controlling for adolescents' age, socioeconomic variables, population density of residence, self-rated health, and survey year, adjusted analyses of adolescent substance users indicated elevated odds of substance-related disorders among Native Americans, adolescents of multiple race/ethnicity, adolescents of

  17. Seasonal variations of nitric oxide flux from agricultural soils in the Southeast United States

    Science.gov (United States)

    Aneja, Viney P.; Robarge, Wayne P.; Sullivan, Lee J.; Moore, Thomas C.; Pierce, Thomas E.; Geron, Chris; Gay, Bruce

    1996-11-01

    Fluxes of nitric oxide (NO) were measured from the summer of 1994 to the spring of 1995 from an intensively managed agricultural soil using a dynamic flow through chamber technique in order to study the seasonal variability in the emissions of NO. The measurements were made on a Norfolk sandy loam (Fine-Loamy, Siliceous, Thermic Typic Paleudult) soil located at an agricultural research station in the Upper Coastal Plain region of North Carolina. Soil nitric oxide fluxes from 3 crops, representing 3 levels of fertilizer application (corn, 168kgNha1; cotton, 68kgNha1; and soybean, 0kgNha1), were measured in each season (summer, fall, winter, and spring). Additional measured soil parameters included soil temperature, soil water content (expressed as percent water filled pore space,%WFPS), and extractable nitrogen. The greatest NO flux observed in each crop occurred during the summer (June to August) measurement period (corn, 21.9±18.6ngNm2 s1; cotton, 4.3±3.7ngNm2 s1; and soybean, 2.1±0.9ngNm2 s1). NO flux decreased in each crop through the fall months to a minimum flux in the winter. Application of fertilizer during the spring months once again produced substantial NO flux, but not as high as during the summer months. Over 80% of NO flux from the three crops measured occurred in the summer months with an estimated 5% of the nitrogen applied as fertilizer emitted as NO in a year's time. The corn crop, which had the highest amount of applied fertilizer, had the highest average yearly NO flux (7.0±4.8ngNm2 s1) followed by cotton and soybean in order (1.7±1.2ngNm2 s1 and 1.0±0.3ngNm2 s-1, respectively). NO flux from soil tracked soil temperature very closely throughout the year, especially through the summer and spring months. However, NO flux measured under a cotton canopy decreased when soil temperature was>25°C and soil moisture content wasassumption that in the Southeast United States, which has naturally emitted VOC's and large acreages of fertilized

  18. Advanced Stirling Convertor Heater Head Durability and Reliability Quantification

    Science.gov (United States)

    Krause, David L.; Shah, Ashwin R.; Korovaichuk, Igor; Kalluri, Sreeramesh

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for long duration Science missions, such as lunar applications, Mars rovers, and deep space missions, that require reliable design lifetimes of up to 17 years. Resistance to creep deformation of the MarM-247 heater head (HH), a structurally critical component of the ASRG Advanced Stirling Convertor (ASC), under high temperatures (up to 850 C) is a key design driver for durability. Inherent uncertainties in the creep behavior of the thin-walled HH and the variations in the wall thickness, control temperature, and working gas pressure need to be accounted for in the life and reliability prediction. Due to the availability of very limited test data, assuring life and reliability of the HH is a challenging task. The NASA Glenn Research Center (GRC) has adopted an integrated approach combining available uniaxial MarM-247 material behavior testing, HH benchmark testing and advanced analysis in order to demonstrate the integrity, life and reliability of the HH under expected mission conditions. The proposed paper describes analytical aspects of the deterministic and probabilistic approaches and results. The deterministic approach involves development of the creep constitutive model for the MarM-247 (akin to the Oak Ridge National Laboratory master curve model used previously for Inconel 718 (Special Metals Corporation)) and nonlinear finite element analysis to predict the mean life. The probabilistic approach includes evaluation of the effect of design variable uncertainties in material creep behavior, geometry and operating conditions on life and reliability for the expected life. The sensitivity of the uncertainties in the design variables on the HH reliability is also quantified, and guidelines to improve reliability are discussed.

  19. Spatial and temporal variations of screening for breast and colorectal cancer in the United States, 2008 to 2012

    Science.gov (United States)

    Feng, Xue; Tan, Xi; Alenzi, Ebtihag O.; Rai, Pragya; Chang, Jongwha

    2016-01-01

    Abstract Cancer screening tests are important tools to combat cancer-related morbidity and mortality. There is limited up-to-date research on spatial and temporal variations of colorectal and breast cancer screening in the United States. County-level data of cancer screening adherence rates were generated from 2008 to 2012 Behavioral Risk Factor Surveillance System. We performed the univariate local indicators for spatial analyses (LISA) for the geographic differences of screening adherence rate and the differential LISA for the change of screening adherence rate from 2008 to 2012. In the univariate LISA, low-to-low clusters were consistently identified in counties of New Mexico, Wyoming, and Mississippi (P cancer screening adherence rate across the United States. We found low-to-low clusters over time in adherence to screening guidelines for both cancer types in New Mexico, Wyoming, and Mississippi, and clusters of potential decrease in adherence to mammography screening guideline in counties of Indiana. The study also showed improvement on mammography screening clustered in southern Appalachia. The methodology adopted in this study identified areas with clusters of consistent low adherence to screening and a decrease in adherence, which implies that further research and intervention is warranted. PMID:28002335

  20. Visual Impairment in Preschool Children in the United States: Demographic and Geographic Variations From 2015 to 2060.

    Science.gov (United States)

    Varma, Rohit; Tarczy-Hornoch, Kristina; Jiang, Xuejuan

    2017-06-01

    Visual impairment (VI) in early childhood can significantly impair development. To determine demographic and geographic variations in VI in children aged 3 to 5 years in the United States in 2015 and to estimate projected prevalence through 2060. Descriptive study reporting statistics estimated based on prevalence data from 2 major population-based studies conducted in the United States between 2003 and 2011. Using US census projections, prevalence of VI and cause-specific VI in the better eye were reported by race/ethnicity, state and region, and per capita prevalence of VI by state. The study included preschool children in the United States. Analyses for this study were conducted between February 2016 and March 2017. Prevalence of VI among children aged 3 to 5 years in the United States. In 2015, more than 174 000 children aged 3 to 5 years in the United States were visually impaired. Almost 121 000 of these cases (69%) arose from simple uncorrected refractive error, and 43 000 (25%) from bilateral amblyopia. By 2060, the number of children aged 3 to 5 years with VI is projected to increase by 26%. In 2015, Hispanic white children accounted for the highest number of VI cases (66 000); this group will remain the most affected through 2060, with an increasingly large proportion of cases (37.7% in 2015 and 43.6% in 2060). The racial/ethnic group with the second most VI is projected to shift from non-Hispanic white children (26.3% in 2015 decreasing to 16.5% in 2060) to African American children (24.5% in 2015 and 22.0% in 2060). From 2015 to 2060, the states projected to have the most children with VI are California (26 600 in 2015 and 38 000 in 2060), Texas (21 500 in 2015 and 29 100 in 2060), and Florida (10 900 in 2015 and 13 900 in 2060). These data suggest that the number of preschool children with VI is projected to increase disproportionally, especially among minority populations. Vision screening for refractive error and related eye

  1. Heat Pump Water Heaters and American Homes: A Good Fit?

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Victor; Lekov, Alex; Meyers, Steve; Letschert, Virginie

    2010-05-14

    Heat pump water heaters (HPWHs) are over twice as energy-efficient as conventional electric resistance water heaters, with the potential to save substantial amounts of electricity. Drawing on analysis conducted for the U.S. Department of Energy's recently-concluded rulemaking on amended standards for water heaters, this paper evaluates key issues that will determine how well, and to what extent, this technology will fit in American homes. The key issues include: 1) equipment cost of HPWHs; 2) cooling of the indoor environment by HPWHs; 3) size and air flow requirements of HPWHs; 4) performance of HPWH under different climate conditions and varying hot water use patterns; and 5) operating cost savings under different electricity prices and hot water use. The paper presents the results of a life-cycle cost analysis of the adoption of HPWHs in a representative sample of American homes, as well as national impact analysis for different market share scenarios. Assuming equipment costs that would result from high production volume, the results show that HPWHs can be cost effective in all regions for most single family homes, especially when the water heater is not installed in a conditioned space. HPWHs are not cost effective for most manufactured home and multi-family installations, due to lower average hot water use and the water heater in the majority of cases being installed in conditioned space, where cooling of the indoor environment and size and air flow requirements of HPWHs increase installation costs.

  2. Structural Benchmark Testing for Stirling Convertor Heater Heads

    Science.gov (United States)

    Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) has identified high efficiency Stirling technology for potential use on long duration Space Science missions such as Mars rovers, deep space missions, and lunar applications. For the long life times required, a structurally significant design limit for the Stirling convertor heater head is creep deformation induced even under relatively low stress levels at high material temperatures. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and much creep data is available for the proposed Inconel-718 (IN-718) and MarM-247 nickel-based superalloy materials of construction. However, very little experimental creep information is available that directly applies to the atypical thin walls, the specific microstructures, and the low stress levels. In addition, the geometry and loading conditions apply multiaxial stress states on the heater head components, far from the conditions of uniaxial testing. For these reasons, experimental benchmark testing is underway to aid in accurately assessing the durability of Stirling heater heads. The investigation supplements uniaxial creep testing with pneumatic testing of heater head test articles at elevated temperatures and with stress levels ranging from one to seven times design stresses. This paper presents experimental methods, results, post-test microstructural analyses, and conclusions for both accelerated and non-accelerated tests. The Stirling projects use the results to calibrate deterministic and probabilistic analytical creep models of the heater heads to predict their life times.

  3. Optimal Heater Control with Technology of Fault Tolerance for Compensating Thermoforming Preheating System

    Directory of Open Access Journals (Sweden)

    Zhen-Zhe Li

    2015-01-01

    Full Text Available The adjustment of heater power is very important because the distribution of thickness strongly depends on the distribution of sheet temperature. In this paper, the steady state optimum distribution of heater power is searched by numerical optimization in order to get uniform sheet temperature. In the following step, optimal heater power distribution with a damaged heater was found out using the technology of fault tolerance, which will be used to reduce the repairing time when some heaters are damaged. The merit of this work is that the design variable was the power of each heater which can be directly used in the preheating process of thermoforming.

  4. Generation of ionospheric ducts by the HAARP HF heater

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, J A; Pradipta, R; Burton, L M; Labno, A; Lee, M C [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Watkins, B J; Fallen, C [University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Kuo, S P [New York University, Brooklyn, NY 11201 (United States); Burke, W J [Air Force Research Laboratory, Hanscom AFB, MA 01731 (United States); Mabius, D; See, B Z, E-mail: mclee@mit.edu [Boston University, Boston, MA 02215 (United States)

    2010-12-15

    We report an investigation of ionospheric ducts having the shape of large plasma sheets, generated by vertically transmitted HAARP HF heater waves in several experiments conducted in Gakona, Alaska. Theory predicts that O-mode heater wave-created ionospheric ducts form parallel-plate waveguides within the meridional plane, and those generated by the X-mode heater waves are orthogonal to the meridional plane. Our theoretical prediction is supported by measurements of ionosonde data (namely ionograms), range-time-intensity (RTI) plots of UHF and HF backscatter radars, as well as magnetometer data analyses. When these plasma sheets experienced ExB drifts, they were intercepted by the HAARP UHF radar and seen as slanted stripes in the RTI plots. This striking feature was also observed in our earlier experiments using the Arecibo UHF radar.

  5. Development of a cost effective microscope heater stage

    Science.gov (United States)

    Dugre, Joshua; Prayaga, Chandra; Wade, Aaron

    Utilizing 3D printing technology, a heater stage has been developed and implemented for microscopic systems. Due to the flexibility of 3D printing,the heater stage can be easily modified to fit any sample size with only slight modifications to the heating element being required. The sample in contact with the heating element can also easily be secured in a thermal insulator, such as aluminum foil. The thermal gradient of the heater stage has been recorded to be less than 1°C and has been compared to more expensive designs, and the cost effectiveness of the system has been determined. The system has been tested with a sample of the liquid crystal 8CB in order to determine the exact temperatures of the phase transitions of the crystal to verify that the system is applicable to a wide range of experimental physics. UWF Quality Enhancement Plan Award.

  6. Flat plate solar air heater with latent heat storage

    Science.gov (United States)

    Touati, B.; Kerroumi, N.; Virgone, J.

    2017-02-01

    Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

  7. Process for thermal imaging scanning of a swaged heater for an anode subassembly of a hollow cathode assembly

    Science.gov (United States)

    Patterson, Michael J. (Inventor); Verhey, Timothy R. R. (Inventor); Soulas, George C. (Inventor)

    2004-01-01

    A process for thermal imaging scanning of a swaged heater of an anode subassembly of a hollow cathode assembly, comprising scanning a swaged heater with a thermal imaging radiometer to measure a temperature distribution of the heater; raising the current in a power supply to increase the temperature of the swaged heater; and measuring the swaged heater temperature using the radiometer, whereupon the temperature distribution along the length of the heater shall be less than plus or minus 5 degrees C.

  8. Performance of Thermosyphon Solar Water Heaters in Series

    Directory of Open Access Journals (Sweden)

    Tsong-Sheng Lee

    2012-08-01

    Full Text Available More than a single thermosyphon solar water heater may be employed in applications when considerable hot water consumption is required. In this experimental investigation, eight typical Taiwanese solar water heaters were connected in series. Degree of temperature stratification and thermosyphon flow rate in a horizontal tank were evaluated. The system was tested under no-load, intermittent and continuous load conditions. Results showed that there was stratification in tanks under the no-load condition. Temperature stratification also redeveloped after the draw-off. Analysis of thermal performance of the system was conducted for each condition.

  9. Development of heat pipes for solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Akyurt, M.

    1984-01-01

    Numerous heat pipes were designed, manufactured, and filled on a specially developed filling rig. Each heat pipe was incorporated into a prototype solar water heater developed for this purpose, and was tested under actual insolation conditions. An extensive testing program lasting for more than a year revealed that the heat pipes perform satisfactorily as heat transfer elements in solar water heaters. A special heat pipe featuring a compact and effective condenser configuration was also tested. It was observed to likewise exhibit isothermal behavior and hence promised potential for large scale solar applications.

  10. Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

    Directory of Open Access Journals (Sweden)

    Valeria Toffoli

    2013-12-01

    Full Text Available The design and characteristics of a micro-system for thermogravimetric analysis (TGA in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

  11. Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression in Brassica rapa Fast Plants

    Science.gov (United States)

    Smith, Amber R.; Williams, Paul H.; McGee, Seth A.; Dósa, Katalin; Pfammatter, Jesse

    2014-01-01

    Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics. PMID:25185225

  12. Numerical and experimental study on heat pump water heater with PCM for thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Long, Jian-You; Zhu, Dong-Sheng [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education, Academy of Chemistry and Energy, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    2008-07-01

    An air source heat pump water heater with phase change material (PCM) for thermal storage was designed to take advantage of off-peak electrical energy. The heat transfer model of PCM was based upon a pure conduction formulation. Quasi-steady state method was used to calculate the temperature distribution and phase front location of PCM during thermal storage process. Temperature and thermal resistance iteration approach has been developed for the analysis of temperature variation of heat transfer fluid (HTF) and phase front location of PCM during thermal release process. To test the physical validity of the calculational results, experimental studies about storing heat and releasing heat of PCM were carried. Comparison between the calculational results and the experimental data shows good agreement. Graphical results including system pressure and input power of heat pump, time-wise variation of stored and released thermal energy of PCM were presented and discussed. (author)

  13. Thermal injuries caused by ignition of volatile substances by gas water heaters.

    Science.gov (United States)

    Rutan, R L; Desai, M H; Herndon, D N

    1993-01-01

    Based on the cumulative data of this tertiary care facility over the past 25 years, one out of every 70 pediatric patients admitted to our institution sustained their injuries during an explosive event instigated by the ignition of volatile substances from gas water heaters. The majority of injuries related to gas water heaters can be prevented by decreasing the temperature setpoint of the heater, by protecting the heater element itself, and by elevating the water heater to 18 inches above the floor. The first two issues have been adequately addressed; however, gas-fueled water heaters continue to be installed at floor level. Current national guidelines are too rigid and do not adequately address water-heater installation in private residences. Although general prevention campaigns target appropriate storage of volatile substances, they rarely address the explosive potential of gas water heaters in combination with combustible fumes.

  14. Diversity of precipitation characteristics in contiguous United States: climatology, interannual variation, and change in the warming climate

    Science.gov (United States)

    Chen, Chen; Chang, Won; Kong, Wenwen; Wang, Jiali; Rao Kotamarthi, V.; Stein, Michael L.; Moyer, Elisabeth J.

    2017-04-01

    Individual precipitation events induce different levels of hydrological impacts given their diverse characteristics, not only in precipitation amount but also in precipitation rate, duration, and size. It thus calls for an understanding of the diversity in precipitation characteristics and its influence on the total precipitation in contiguous United States. The framework we use to look into the precipitation diversity includes three steps: 1. we analyze the precipitation in observations (StageIV, 4kmx4km, 1h) and regional climate models (CCSM4-WRF downscaling,12kmx12km, 3h), in which the high spatio-temporal resolution enables us to "see" individual precipitation events. 2. switching from the Eulerian to Lagrangian perspective, we track individual rainstorms using Chang et al. (2016), in which algorithm both small and big events are identified to ensure the full spectrum diversity. 3. we use a set of metrics to characterize varying aspects of diversity and decompose their contributions to the total precipitation in CONUS. We also measure the variation and change in event frequency. The overall understandings are the following: 1. as to the climatology, though certain rainstorms with longer duration or larger size have better abilities to produce precipitation, the scarcity limits their overall contributions to the seasonal precipitation in CONUS. 2. as to the interannual variation, for a wetter year when the total precipitation is larger than normal and events are more frequent, the averaged rainstorm size is larger though the intensified precipitation rate shortens the rainstorm duration. 3. as to the change in a warming climate (as in Chang et al. 2016), CCSM4-WRF projection under RCP8.5 scenario suggests that, along with the increasing precipitation amount and intensity, the averaged rainstorm duration become longer but the size becomes overall smaller. The total number of events does not change much. 4. different relations governing the interannual variation

  15. High-Temperature Compatible Nickel Silicide Thermometer And Heater For Catalytic Chemical Microreactors

    DEFF Research Database (Denmark)

    Jensen, Søren; Quaade, U.J.; Hansen, Ole

    2005-01-01

    Integration of heaters and thermometers is important for agile and accurate control and measurement of the thermal reaction conditions in microfabricated chemical reactors (microreactors). This paper describes development and operation of nickel silicide heaters and temperature sensors...... for temperatures exceeding 700 °C. The heaters and thermometers are integrated with chemical microreactors for heterogeneous catalytic conversion of gasses, and thermally activated catalytic conversion of CO to CO2 in the reactors is demonstrated. The heaters and thermometers are shown to be compatible...

  16. Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Petersen, Joseph M.; Parker, Graham B.; Baechler, Michael C.

    2014-07-21

    Increasing penetration of heat pump water heaters (HPWHs) in the residential sector will offer an important opportunity for energy savings, with a theoretical energy savings of up to 63% per water heater and up to 11% of residential energy use (EIA 2009). However, significant barriers must be overcome before this technology will reach widespread adoption in the Pacific Northwest region and nationwide. One significant barrier noted by the Northwest Energy Efficiency Alliance (NEEA) is the possible interaction with the homes’ space conditioning system for units installed in conditioned spaces. Such complex interactions may decrease the magnitude of whole-house savings available from HPWH installed in the conditioned space in cold climates and could lead to comfort concerns (Larson et al. 2011; Kresta 2012). Modeling studies indicate that the installation location of HPWHs can significantly impact their performance and the resultant whole-house energy savings (Larson et al. 2012; Maguire et al. 2013). However, field data are not currently available to validate these results. This field evaluation of two GE GeoSpring HPWHs in the PNNL Lab Homes is designed to measure the performance and impact on the Lab Home HVAC system of a GE GeoSpring HPWH configured with exhaust ducting compared to an unducted GeoSpring HPWH during heating and cooling season periods; and measure the performance and impact on the Lab Home HVAC system of the GeoSpring HPWH with both supply and exhaust air ducting as compared to an unducted GeoSpring HPWH during heating and cooling season periods. Important metrics evaluated in these experiments include water heater energy use, HVAC energy use, whole house energy use, interior temperatures (as a proxy for thermal comfort), and cost impacts. This technical report presents results from the PNNL Lab Homes experiment.

  17. 77 FR 74559 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2012-12-17

    ... descriptors (i.e., thermal efficiency and pool heater heating seasonal efficiency), as well as seasonal energy... thermal efficiency metric for pool heaters, but did not propose an integrated annual fuel utilization... states that for pool heaters, the descriptor shall be thermal efficiency. (42 U.S.C....

  18. 30 CFR 75.341 - Direct-fired intake air heaters.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Direct-fired intake air heaters. 75.341 Section... air heaters. (a) If any system used to heat intake air malfunctions, the heaters affected shall switch off automatically. (b) Thermal overload devices shall protect the blower motor from overheating....

  19. 46 CFR 61.30-5 - Preparation of thermal fluid heater for inspection and test.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Preparation of thermal fluid heater for inspection and... ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-5 Preparation of thermal fluid heater for inspection and test. For visual inspection, access plates and...

  20. 76 FR 63211 - Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating...

    Science.gov (United States)

    2011-10-12

    ... descriptors (i.e., thermal efficiency and pool heater heating seasonal efficiency), as well as seasonal energy... ``efficiency descriptor,'' EPCA specifies that for pool heaters, the efficiency descriptor shall be ``thermal efficiency.'' (42 U.S.C. 6291(22)(E)) Further, EPCA defines the ``thermal efficiency of pool heaters'' as...

  1. Recovery Act: Water Heater ZigBee Open Standard Wireless Controller

    Energy Technology Data Exchange (ETDEWEB)

    Butler, William P. [Emerson Electric Co., St. Louis, MO (United States); Buescher, Tom [Emerson Electric Co., St. Louis, MO (United States)

    2014-04-30

    The objective of Emerson's Water Heater ZigBee Open Standard Wireless Controller is to support the DOE's AARA priority for Clean, Secure Energy by designing a water heater control that levels out residential and small business peak electricity demand through thermal energy storage in the water heater tank.

  2. TOTAL PARTICLE, SULFATE, AND ACIDIC AEROSOL EMISSIONS FROM KEROSENE SPACE HEATERS

    Science.gov (United States)

    Chamber studies were conducted on four unvented kerosene space heaters to assess emissions of total particle, sulfate, and acidic aerosol. The heaters tested represented four burner designs currently in use by the public. Kerosene space heaters are a potential source of fine part...

  3. 40 CFR 63.7506 - Do any boilers or process heaters have limited requirements?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Do any boilers or process heaters have limited requirements? 63.7506 Section 63.7506 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... or process heaters have limited requirements? (a) New or reconstructed boilers and process heaters...

  4. Compositional variation within thick (>10 m) flow units of Mauna Kea Volcano cored by the Hawaii Scientific Drilling Project

    Science.gov (United States)

    Huang, Shichun; Vollinger, Michael J.; Frey, Frederick A.; Rhodes, J. Michael; Zhang, Qun

    2016-07-01

    Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from 100 m. Geochemical heterogeneity in thin flows may be created by interaction with the surficial environment whereas magmatic processes occurring during emplacement may create geochemical heterogeneities in thick flows. The Hawaii Scientific Drilling Project (HSDP) cored ∼3.3 km of basalt erupted at Mauna Kea Volcano. In order to determine geochemical heterogeneities in a flow, multiple samples from four thick (9.3-98.4 m) HSDP flow units were analyzed for major and trace elements. We found that major element abundances in three submarine flow units are controlled by the varying proportion of olivine, the primary phenocryst phase in these samples. Post-magmatic alteration of a subaerial flow led to loss of SiO2, CaO, Na2O, K2O and P2O5, and as a consequence, contents of immobile elements, such as Fe2O3 and Al2O3, increase. The mobility of SiO2 is important because Mauma Kea shield lavas divide into two groups that differ in SiO2 content. Post-magmatic mobility of SiO2 adds complexity to determining if these groups reflect differences in source or process. The most mobile elements during post-magmatic subaerial and submarine alteration are K and Rb, and Ba, Sr and U were also mobile, but their abundances are not highly correlated with K and Rb. The Ba/Th ratio has been used to document an important role for a plagioclase-rich source component for basalt from the Galapagos, Iceland and Hawaii. Although Ba/Th is anomalously high in Hawaiian basalt, variation in Ba abundance within a single flow shows that it is not a reliable indicator of a deep source component. In contrast, ratios involving elements that are typically immobile, such as La/Nb, La

  5. Solar water heaters in China: A new day dawning

    NARCIS (Netherlands)

    Han, Jingyi; Mol, A.P.J.; Lu, Y.

    2010-01-01

    Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively

  6. Fast thermal nanoimprint lithography by a stamp with integrated heater

    DEFF Research Database (Denmark)

    Tormen, Massimo; Malureanu, Radu; Pedersen, Rasmus Haugstrup

    2008-01-01

    We propose fast nanoimprinting lithography (NIL) process based on the use of stamps with integrated heater. The latter consists of heavily ion implantation n-type doped silicon layer buried below the microstructured surface of the stamp. The stamp is heated by Joule effect, by 50 μs 25 Hz...

  7. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  8. 14 CFR 25.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... passages. (b) Ventilating air ducts. Each ventilating air duct passing through any fire zone must be..., the ventilating air duct downstream of each heater must be fireproof for a distance great enough to... fluids or vapors into the ventilating airstream. (c) Combustion air ducts. Each combustion air duct...

  9. 14 CFR 23.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... passage that surrounds the combustion chamber. (b) Ventilating air ducts. Each ventilating air duct... fireproof valves or by equally effective means, the ventilating air duct downstream of each heater must be...) Combustion air ducts. Each combustion air duct must be fireproof for a distance great enough to...

  10. CHARACTERIZATION OF POPULATION AND USAGE OF UNVENTED KEROSENE SPACE HEATERS

    Science.gov (United States)

    The report gives results of a study of the market penetration of unvented kerosene space heaters (UKSHs) in the residential sector, The study was aimed at gathering baseline information to help assess the magnitude and potential severity of a problem involving emissions from unve...

  11. Thermomechanics of the granular bed T-joint water heater

    Science.gov (United States)

    Teplitskii, Yu. S.; Belonovich, D. G.

    2012-11-01

    On the basis of the heat transfer model taking into account the radiative transport the temperature distribution and the resistance of the water heater with a granular packing having two independent air inlets have been investigated. The generalized dependence for calculating the resistance of the granular bed has been obtained.

  12. an automatic safety control for immersion water heater

    African Journals Online (AJOL)

    NIJOTECH

    heater in the Nigerian market in its current form is depicted ... the comparator used is an open collector type. It is instructive to take a close look at the operation of the Schmitt trigger. The equivalent .... additional advantage of keeping the water.

  13. Electrothermal pumping with interdigitated electrodes and resistive heaters.

    Science.gov (United States)

    Williams, Stuart J; Green, Nicolas G

    2015-08-01

    Interdigitated electrodes are used in electrokinetic lab-on-a-chip devices for dielectrophoretic trapping and characterization of suspended particles, as well as the production of field-induced fluid flow via AC electroosomosis and electrothermal mechanisms. However, the optimum design for dielectrophoresis, that if symmetrical electrodes, cannot induce bulk electrohydrodynamic pumping. In addition, the mechanism of intrinsic electrothermal pumping is affected by the properties of the fluid, with thermal fields being generated by Joule Heating. This work demonstrates the incorporation of an underlying thin film heater, electrically isolated from the interdigitated electrodes by an insulator layer, to enhance bulk electrothermal pumping. The use of integrated heaters allows the thermal field generation to be controlled independently of the electric field. Numerical simulations are performed to demonstrate the importance of geometrical arrangement of the heater with respect to the interdigitated electrodes, as well as electrode size, spacing, and arrangement. The optimization of such a system is a careful balance between electrokinetics, heat transfer, and fluid dynamics. The heater location and electrode spacing influence the rate of electrothermal pumping significantly more than electrode width and insulator layer thickness. This demonstration will aid in the development of microfluidic electrokinetic systems that want to utilize the advantages associated with electrothermal pumping while simultaneously applying other lab-on-a-chip electrokinetics like dielectrophoresis.

  14. Evaluation of the Demand Response Performance of Electric Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parker, Steven A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Richard M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, Forrest S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    The purpose of this project is to verify or refute many of the concerns raised by utilities regarding the ability of large tank HPWHs to perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. This project was divided into three phases. Phase 1 consisted of week-long laboratory experiments designed to demonstrate technical feasibility of individual large-tank HPWHs in providing DR services compared to large-tank ERWHs. In Phase 2, the individual behaviors of the water heaters were then extrapolated to a population by first calibrating readily available water heater models developed in GridLAB-D simulation software to experimental results obtained in Phase 1. These models were used to simulate a population of water heaters and generate annual load profiles to assess the impacts on system-level power and residential load curves. Such population modeling allows for the inherent and permanent load reduction accomplished by the more efficient HPWHs to be considered, in addition to the temporal DR services the water heater can provide by switching ON or OFF as needed by utilities. The economic and emissions impacts of using large-tank water heaters in DR programs are then analyzed from the utility and consumer perspective, based on National Impacts Analysis in Phase 3. Phase 1 is discussed in this report. Details on Phases 2 and 3 can be found in the companion report (Cooke et al. 2014).

  15. Study of the distribution of the absorbed solar radiation on the performance of a CPC-type ICS water heater

    Energy Technology Data Exchange (ETDEWEB)

    Souliotis, M.; Tripanagnostopoulos, Y. [Physics Department, University of Patras, 26504 Patras (Greece)

    2008-05-15

    An Integrated Collector Storage (ICS) solar water heater was designed, constructed and studied with an emphasis on its optical and thermal performance. The ICS system consists of one cylindrical horizontal tank properly mounted in a stationary symmetrical Compound Parabolic Concentrating (CPC) reflector trough. The main objective was the design and the construction of a low cost solar system with improved thermal performance based on the exploitation of the non-uniform distribution of the absorbed solar radiation on the cylindrical storage tank surface. A ray-tracing model was developed to gauge the distribution of the incoming solar radiation on the absorber surface and the results were compared with those from a theoretical optical model based on the average number of reflections. The variation of the optical efficiency as function of the incident angle of the incoming solar radiation along with its dependence on the month during annual operation of ICS system is presented. The ICS device was experimentally tested outdoors during a whole year in order to correlate the observed temperature rise and stratification of the stored water with the non-uniform distribution of the absorbed solar radiation. The results show that the upper part of the tank surface collects the larger fraction of the total absorbed solar radiation for all incident angles throughout the year. This is found to have a significant effect on the overall thermal performance of the ICS unit. In addition, the presented results can be considered important for the design and the operation of ICS systems consisting of cylindrical tank and CPC reflectors. (author)

  16. Three-phase heaters with common overburden sections for heating subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J [Bellaire, TX

    2012-02-14

    A heating system for a subsurface formation is described. The heating system includes three substantially u-shaped heaters with first end portions of the heaters being electrically coupled to a single, three-phase wye transformer and second end portions of the heaters being electrically coupled to each other and/or to ground. The three heaters may enter the formation through a first common wellbore and exit the formation through a second common wellbore so that the magnetic fields of the three heaters at least partially cancel out in the common wellbores.

  17. Assessment of variation in the alberta context tool: the contribution of unit level contextual factors and specialty in Canadian pediatric acute care settings

    Directory of Open Access Journals (Sweden)

    Cummings Greta G

    2011-10-01

    Full Text Available Abstract Background There are few validated measures of organizational context and none that we located are parsimonious and address modifiable characteristics of context. The Alberta Context Tool (ACT was developed to meet this need. The instrument assesses 8 dimensions of context, which comprise 10 concepts. The purpose of this paper is to report evidence to further the validity argument for ACT. The specific objectives of this paper are to: (1 examine the extent to which the 10 ACT concepts discriminate between patient care units and (2 identify variables that significantly contribute to between-unit variation for each of the 10 concepts. Methods 859 professional nurses (844 valid responses working in medical, surgical and critical care units of 8 Canadian pediatric hospitals completed the ACT. A random intercept, fixed effects hierarchical linear modeling (HLM strategy was used to quantify and explain variance in the 10 ACT concepts to establish the ACT's ability to discriminate between units. We ran 40 models (a series of 4 models for each of the 10 concepts in which we systematically assessed the unique contribution (i.e., error variance reduction of different variables to between-unit variation. First, we constructed a null model in which we quantified the variance overall, in each of the concepts. Then we controlled for the contribution of individual level variables (Model 1. In Model 2, we assessed the contribution of practice specialty (medical, surgical, critical care to variation since it was central to construction of the sampling frame for the study. Finally, we assessed the contribution of additional unit level variables (Model 3. Results The null model (unadjusted baseline HLM model established that there was significant variation between units in each of the 10 ACT concepts (i.e., discrimination between units. When we controlled for individual characteristics, significant variation in the 10 concepts remained. Assessment of the

  18. Impact of Pilot Light Modeling on the Predicted Annual Performance of Residential Gas Water Heaters: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.

    2013-08-01

    Modeling residential water heaters with dynamic simulation models can provide accurate estimates of their annual energy consumption, if the units? characteristics and use conditions are known. Most gas storage water heaters (GSWHs) include a standing pilot light. It is generally assumed that the pilot light energy will help make up standby losses and have no impact on the predicted annual energy consumption. However, that is not always the case. The gas input rate and conversion efficiency of a pilot light for a GSWH were determined from laboratory data. The data were used in simulations of a typical GSWH with and without a pilot light, for two cases: 1) the GSWH is used alone; and 2) the GSWH is the second tank in a solar water heating (SWH) system. The sensitivity of wasted pilot light energy to annual hot water use, climate, and installation location was examined. The GSWH used alone in unconditioned space in a hot climate had a slight increase in energy consumption. The GSWH with a pilot light used as a backup to an SWH used up to 80% more auxiliary energy than one without in hot, sunny locations, from increased tank losses.

  19. Savings on natural gas consumption by doubling thermal efficiencies of balanced-flue space heaters

    Energy Technology Data Exchange (ETDEWEB)

    Juanico, Luis E. [Conicet, and Centro Atomico Bariloche e Instituto Balseiro, Av. Bustillo 9500, 8400 Bariloche, Rio Negro (Argentina); Gonzalez, Alejandro D. [Grupo de Estudios Ambientales, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (Inibioma-Conicet), 8400 Bariloche, Rio Negro (Argentina)

    2008-07-01

    Natural gas is a relatively clean fossil fuel for space heating. However, when it is not used efficiently high consumption can become an environmental problem. In Argentina, individual balanced-flue space heaters are the most extensively used in temperate and cold regions. This furnace is a simple device with a burner set into a metal chamber, separated from the indoor ambient by an enclosing cabinet, and both inlet and outgas chimneys are connected to the outdoor ambient. In previous studies, we measured the performance of these commercial devices, and found very low thermal efficiency (in the range of 39-63% depending on the chimney configuration). The extensive use of these devices is possible due to the availability of unlimited amount of subsidised natural gas to households and businesses. In the present work, we developed a prototype with simple and low cost modifications made on commercial models, and measured the improvements on the thermal efficiency. Findings showed better infrared radiation, enhanced indoor air convection, and passive chimney flow regulation leading to thermal efficiency in the range of 75-85%. These values represent an improvement of 100% when compared to marketed models, and hence, the specific cost of the heater per unit of useful heating power delivered was actually reduced. Considering the large market presence of these furnaces in both residential and business sectors in Argentina, the potential benefits related to gas consumption and environmental emissions are very significant. (author)

  20. 10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...

    Science.gov (United States)

    2010-01-01

    ... attached. Thermal efficiency for an instantaneous water heater, a storage water heater or a hot water... the amount of energy consumed by the water heater as measured during the thermal efficiency test... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial water heaters, hot...

  1. Possible conservation units of the sun bear (Helarctos malayanus) in Sarawak based on variation of mtDNA control region.

    OpenAIRE

    ONUMA, Manabu; SUZUKI, Masatsugu; Ohtaishi, Noriyuki

    2006-01-01

    The mitochondrial DNA control region of the sun bear(Helarctos malayanus) was sequenced using 21DNA samples collected from confiscated sun bears to identify conservation units, such as evolutionarily significant units and management units, in Sarawak, Borneo Island. A total of 10 haplotypes were observed, indicating the presence of at least two lineages in the sun bear population in Sarawak. Presumably, these two lineages could represent evolutionarily significant units. How...

  2. An Active Heater Control Concept to Meet IXO Type Mirror Module Thermal-Structural Distortion Requirement

    Science.gov (United States)

    Choi, Michael

    2013-01-01

    Flight mirror assemblies (FMAs) of large telescopes, such as the International X-ray Observatory (IXO), have very stringent thermal-structural distortion requirements. The spatial temperature gradient requirement within a FMA could be as small as 0.05 C. Con ventionally, heaters and thermistors are attached to the stray light baffle (SLB), and centralized heater controllers (i.e., heater controller boards located in a large electronics box) are used. Due to the large number of heater harnesses, accommodating and routing them is extremely difficult. The total harness length/mass is very large. This innovation uses a thermally conductive pre-collimator to accommodate heaters and a distributed heater controller approach. It minimizes the harness length and mass, and reduces the problem of routing and accommodating them. Heaters and thermistors are attached to a short (4.67 cm) aluminum portion of the pre-collimator, which is thermally coupled to the SLB. Heaters, which have a very small heater power density, and thermistors are attached to the exterior of all the mirror module walls. The major portion (23.4 cm) of the pre-collimator for the middle and outer modules is made of thin, non-conductive material. It minimizes the view factors from the FMA and heated portion of the precollimator to space. It also minimizes heat conduction from one end of the FMA to the other. Small and multi-channel heater controllers, which have adjustable set points and internal redundancy, are used. They are mounted to the mechanical support structure members adjacent to each module. The IXO FMA, which is 3.3 m in diameter, is an example of a large telescope. If the heater controller boards are centralized, routing and accommodating heater harnesses is extremely difficult. This innovation has the following advantages. It minimizes the length/mass of the heater harness between the heater controllers and heater circuits. It reduces the problem of routing and accommodating the harness on the

  3. Evaluation of candidate Stirling engine heater tube alloys after 3500 hours exposure to high pressure doped hydrogen or helium

    Science.gov (United States)

    Misencik, J. A.; Titran, R. H.

    1984-01-01

    The heater head tubes of current prototype automotive Stirling engines are fabricated from alloy N-155, an alloy which contains 20 percent cobalt. Because the United States imports over 90 percent of the cobalt used in this country and resource supplies could not meet the demand imposed by automotive applications of cobalt in the heater head (tubes plus cylinders and regenerator housings), it is imperative that substitute alloys free of cobalt be identified. The research described herein focused on the heater head tubes. Sixteen alloys (15 potential substitutes plus the 20 percent Co N-155 alloy) were evaluated in the form of thin wall tubing in the NASA Lewis Research Center Stirling simulator materials diesel fuel fired test rigs. Tubes filled with either hydrogen doped with 1 percent CO2 or with helium at a gas pressure of 15 MPa and a temperature of 820 C were cyclic endurance tested for times up to 3500 hr. Results showed that two iron-nickel base superalloys, CG-27 and Pyromet 901 survived the 3500 hr endurance test. The remaining alloys failed by creep-rupture at times less than 3000 hr, however, several other alloys had superior lives to N-155. Results further showed that doping the hydrogen working fluid with 1 vol % CO2 is an effective means of reducing hydrogen permeability through all the alloy tubes investigated.

  4. Electrical heater for very-low pressure helium gas

    CERN Document Server

    Benda, V; Vuillierme, B

    1996-01-01

    Testing superconducting magnets for the Large Hadron Collider (LHC) in superfluid helium requires large-capacity refrigeration at 1.8K. At CERN, this is provided by a combination of a cold compressor and a set of warm vacuum pumps capable of handling up to 18g/s at 1 kPa suction pressure. The cold helium vapour, after the cold compressor, is warmed up from about 5K to ambient temperature in a 32 kW electrical heater. The device is designed to operate reliably at flow rates varying from 1 to 18g/s, inlet pressure of 1 kPa to 3 kPa, with pressure drop 100 Pa. Design and construction of the heater, completely realised at CERN, are presented, as well as measured performance. Some technological problems are discussed.

  5. Thermal hydraulic analysis of the annular flow helium heater design

    Science.gov (United States)

    Chen, N. C.; Sanders, J. P.

    1982-05-01

    Core support performance test (CSPT) by use of an existing facility, components flow test loop (CFTL), as part of the high temperature gas cooled reactor (HTGR) application program were conducted. A major objective of the CSPT is to study accelerated corrosion of the core graphite support structure in helium at reactor conditions. Concentration of impurities will be adjusted so that a 6 month test represents the 30 year reactor life. Thermal hydraulic and structural integrity of the graphite specimen, will be studied at high pressure of 7.24 MPa (1050 psi) and high temperature of 1000 deg C in a test vessel. To achieve the required high temperature at the test section, a heater bundle has to be specially designed and properly manufactured. Performance characteristics of the heater which were determined from an analysis based on this design are presented.

  6. DESIGN OF A 500W RESONANT INDUCTION HEATER

    Directory of Open Access Journals (Sweden)

    Bekir Sami SAZAK

    1999-01-01

    Full Text Available In this paper a complete design procedure for a 500W induction heating system is given. An induction heating system basically consists of a coil and a DC/AC inverter. The use of a single switch resonant inverter, which is operated with Discontinuous Conduction Mode (DCM, allows the switching device to turn off under zero current conditions, therefore switching losses are much reduced. This inverter system transforms the DC into AC for the induction heater coil. The proposed coil design method is applicable to a load of any shape so long as the coil surrounds the workpiece. The basis of this method of coil design is the reduction of the induction heater coil and workpiece to their equivalent resistance and inductance.

  7. Development of Exhaust Gas Driven Absorption Chiller-Heater

    Science.gov (United States)

    Inoue, Naoyuki; Endou, Tetsuya; Saito, Kiyoshi; Kawai, Sunao

    Waste heat from co-generation systems are usually recovered by hot water or steam, those are used to drive absorption refrigerators at cooling time, and those are used for heating via heat exchangers at heating time. However waste heat from micro gas turbines are discharged in the form of exhaust gas, it is simple that exhaust gas is directly supplied to absorption chiller-heaters. In the first report we studied cooling cycle, and this second paper, we evaluated various absorption heating cycles for exhaust gas driven absorption chiller-heaters, and adopted one of these cycles for the prototype machine. Also, we experimented with the prototype for wide range condition and got the heating characteristics. Based on the experimental data, we developed a simulation model of the static characteristics, and then studied how to increase the output by limited exhaust gas.

  8. An experimental evaluation of multi-pass solar air heaters

    Energy Technology Data Exchange (ETDEWEB)

    Satcunanathan, S.; Persad, P.

    1980-12-01

    Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

  9. Research on Rapid Cooling Technology during Online Maintenance of High-pressure Heater%高压加热器在线检修期间快速冷却技术研究

    Institute of Scientific and Technical Information of China (English)

    李明志; 刘海昌

    2014-01-01

    During units operation, the heater has to be disconnected for online maintenance due to leakage. On the basis of not changing thermal system of high-pressure heater, the compressed air heated by fast cool-ing device is introduced into high-pressure heater. By temperature control of compressed air from outlet of fast cooling device, the heater is cooled fast. The technology can be used to decrease metal temperature of heater in short time and reduce the time of heater cooling and maintenance so that the heater can be resumed soon-er. With the fast cooling technology of heater, temperature of internal metal wall and external wall of heater decreases equally with little differences, which therefore ensures metal property of heater and prevents heater damage due to inappropriate cooling.%机组运行期间,加热器发生泄漏被迫在线解列检修时,在不改变高压加热器热力系统的基础上,将汽轮机快冷装置加热后的压缩空气引入高压加热器,通过控制快冷装置出口压缩空气温度,对加热器进行快速冷却。使用该技术可以在较短时间内降低加热器金属温度,缩短加热器冷却及抢修时间,使加热器可快速恢复使用。由于加热器快冷技术的使用,加热器冷却过程中的金属内外壁温降速度均匀\\温差小,保证加热器金属特性,并避免因加热器冷却不当造成的加热器损坏。

  10. Ethnic Variation in the Prevalence of Visual Impairment in People Attending Diabetic Retinopathy Screening in the United Kingdom (DRIVE UK)

    Science.gov (United States)

    Sivaprasad, Sobha; Gupta, Bhaskar; Gulliford, Martin C.; Dodhia, Hiten; Mann, Samantha; Nagi, Dinesh; Evans, Jennifer

    2012-01-01

    Purpose To provide estimates of visual impairment in people with diabetes attending screening in a multi-ethnic population in England (United Kingdom). Methods The Diabetic Retinopathy In Various Ethnic groups in UK (DRIVE UK) Study is a cross-sectional study on the ethnic variations of the prevalence of DR and visual impairment in two multi-racial cohorts in the UK. People on the diabetes register in West Yorkshire and South East London who were screened, treated or monitored between April 2008 to July 2009 (London) or August 2009 (West Yorkshire) were included in the study. Data on age, gender, ethnic group, visual acuity and diabetic retinopathy were collected. Ethnic group was defined according to the 2011 census classification. The two main ethnic minority groups represented here are Blacks (“Black/African/Caribbean/Black British”) and South Asians (“Asians originating from the Indian subcontinent”). We examined the prevalence of visual impairment in the better eye using three cut-off points (a) loss of vision sufficient for driving (approximately visual impairment (visual impairment (visual impairment in the minority ethnic groups to the age-structure of the white population. Results Data on visual acuity and were available on 50,331individuals 3.4% of people diagnosed with diabetes and attending screening were visually impaired (95% confidence intervals (CI) 3.2% to 3.5%) and 0.39% severely visually impaired (0.33% to 0.44%). Blacks and South Asians had a higher prevalence of visual impairment (directly age standardised prevalence 4.6%, 95% CI 4.0% to 5.1% and 6.9%, 95% CI 5.8% to 8.0% respectively) compared to white people (3.3%, 95% CI 3.1% to 3.5%). Visual loss was also more prevalent with increasing age, type 1 diabetes and in people living in Yorkshire. Conclusions Visual impairment remains an important public health problem in people with diabetes, and is more prevalent in the minority ethnic groups in the UK. PMID:22761840

  11. Comparison of Advanced Residential Water Heating Technologies in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Fang, Xia [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-05-01

    In this study, gas storage, gas tankless, condensing, electric storage, heat pump, and solar water heaters were simulated in several different climates across the United States, installed in both conditioned and unconditioned space and subjected to several different draw profiles. While many pre-existing models were used, new models of condensing and heat pump water heaters were created specifically for this work. In each case modeled, the whole house was simulated along with the water heater to capture any interactions between the water heater and the space conditioning equipment.

  12. Conasauga near-surface heater experiment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, J.L.

    1979-11-01

    The Conasauga Experiment was undertaken to begin assessment of the thermomechanical and chemical response of a specific shale to the heat resulting from emplacement of high-level nuclear wastes. Canister-size heaters were implanted in Conasauga shale in Tennessee. Instrumentation arrays wee placed at various depths in drill holes around each heater. The heaters operated for 8 months and, after the first 4 days, were maintained at 385/sup 0/C. Emphasis was on characterizing the thermal and mechanical response of the formation. Conduction was the major mode of heat transport; convection was perceptible only at temperatures above the boiling point of water. Despite dehydration of the shale at higher temperatures, in situ thermal conductivity was essentially constant and not a function of temperature. The mechanical response of the formation was a slight overall expansion, apparently resulting in a general decrease in permeability. Metallurgical observations were made, the stability of a borosilicate glass wasteform simulant was assessed, and changes in formation mineralogy and groundwater composition were documented. In each of these areas, transient nonequilibrium processes occur that affect material stability and may be important in determining the integrity of a repository. In general, data from the test reflect favorably on the use of shale as a disposal medium for nuclear waste.

  13. Performance Analysis and Modeling of Thermally Sprayed Resistive Heaters

    Science.gov (United States)

    Lamarre, Jean-Michel; Marcoux, Pierre; Perrault, Michel; Abbott, Richard C.; Legoux, Jean-Gabriel

    2013-08-01

    Many processes and systems require hot surfaces. These are usually heated using electrical elements located in their vicinity. However, this solution is subject to intrinsic limitations associated with heating element geometry and physical location. Thermally spraying electrical elements directly on surfaces can overcome these limitations by tailoring the geometry of the heating element to the application. Moreover, the element heat transfer is maximized by minimizing the distance between the heater and the surface to be heated. This article is aimed at modeling and characterizing resistive heaters sprayed on metallic substrates. Heaters were fabricated by using a plasma-sprayed alumina dielectric insulator and a wire flame-sprayed iron-based alloy resistive element. Samples were energized and kept at a constant temperature of 425 °C for up to 4 months. SEM cross-sectional observations revealed the formation of cracks at very specific locations in the alumina layer after thermal use. Finite-element modeling shows that these cracks originate from high local thermal stresses and can be predicted according to the considered geometry. The simulation model was refined using experimental parameters obtained by several techniques such as emissivity and time-dependent temperature profile (infra-red camera), resistivity (four-probe technique), thermal diffusivity (laser flash method), and mechanical properties (micro and nanoindentation). The influence of the alumina thickness and the substrate material on crack formation was evaluated.

  14. Tip Heater for Minimum Quench Energy Measurements on Superconducting Strands

    CERN Document Server

    Bauer, P; Oberli, L R

    1999-01-01

    Superconducting strands can be characterized by their Minimum Quench Energy (MQE), i.e. the minimum heat pulse needed to trigger a quench in operation conditions (field, temperature, current), in the limit of a (temporally and spatially) d-shaped disturbance. The sub-mm/µs range of perturbation space has only recently been achieved using the electrical graphite-paste heater technique [1]. The present work has put this technique into practice for the strands of the LHC main magnets, which are designed to operate at 1.9K in peak fields of up to 9T [1]. No way has been found yet to calibrate MQE measurements. To make relative statements on the MQE of different samples possible, the reproducibility of the measurements was emphasized. First heater prototypes did not come up to this stipulation. Finally the tip-heater configuration was found to meet the requirements. It generates a heat pulse in a thin resistive graphite paste deposit on top of a small tip that is pressed against the sample with a clamp. The clamp...

  15. Control and Coordination of Frequency Responsive Residential Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Tess L.; Kalsi, Karanjit; Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Pratt, Richard M.

    2016-07-31

    Demand-side frequency control can complement traditional generator controls to maintain the stability of large electric systems in the face of rising uncertainty and variability associated with renewable energy resources. This paper presents a hierarchical frequency-based load control strategy that uses a supervisor to flexibly adjust control gains that a population of end-use loads respond to in a decentralized manner to help meet the NERC BAL-003-1 frequency response standard at both the area level and interconnection level. The load model is calibrated and used to model populations of frequency-responsive water heaters in a PowerWorld simulation of the U.S. Western Interconnection (WECC). The proposed design is implemented and demonstrated on physical water heaters in a laboratory setting. A significant fraction of the required frequency response in the WECC could be supplied by electric water heaters alone at penetration levels of less than 15%, while contributing to NERC requirements at the interconnection and area levels.

  16. Solar water heaters. A review of systems research and design innovation

    Energy Technology Data Exchange (ETDEWEB)

    Norton, Brian [Dublin Institute of Technology (Ireland). Dublin Energy Lab.

    2011-07-01

    Solar water heating can be considered to be an established mature technology. The achievement of this status is the outcome of over a century of system development that culminated with a flourish of innovation in the last thirty years. Drivers for research and development have been achieving economic viability by devising systems that, for specific applications in particular climate contexts produced more hot water per unit cost. Reductions in both initial capital and installation costs have been achieved as well as in those associated with subsequent operation and maintenance. Research on solar water heating is discussed with the emphasis on overall systems though some key aspects of component development are also outlined. A comprehensive taxonomy is presented of the generic types of solar water heater that have emerged and their features, characteristics and performance are discussed. (orig.)

  17. High Efficiency Water Heating Technology Development Final Report. Part I, Lab/Field Performance Evaluation and Accelerated Life Testing of a Hybrid Electric Heat Pump Water Heater (HPWH)

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Murphy, Richard W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    DOE has supported efforts for many years with the objective of getting a water heater that uses heat pump technology (aka a heat pump water heater or HPWH) successfully on the residential equipment market. The most recent previous effort (1999-2002) produced a product that performed very well in ORNL-led accelerated durability and field tests. The commercial partner for this effort, Enviromaster International (EMI), introduced the product to the market under the trade name Watter$aver in 2002 but ceased production in 2005 due to low sales. A combination of high sales price and lack of any significant infrastructure for service after the sale were the principal reasons for the failure of this effort. What was needed for market success was a commercial partner with the manufacturing and market distribution capability necessary to allow economies of scale to lead to a viable unit price together with a strong customer service infrastructure. General Electric certainly meets these requirements, and knowing of ORNL s expertise in this area, approached ORNL with the proposal to partner in a CRADA to produce a high efficiency electric water heater. A CRADA with GE was initiated early in Fiscal Year, 2008. GE initially named its product the Hybrid Electric Water Heater (HEWH).

  18. Four Bed Molecular Sieve - Exploration (4BMS-X) Virtual Heater Design and Optimization

    Science.gov (United States)

    Schunk, R. Gregory; Peters, Warren T.; Thomas, John T., Jr.

    2017-01-01

    A 4BMS-X (Four Bed Molecular Sieve - Exploration) design and heater optimization study for CO2 sorbent beds in proposed exploration system architectures is presented. The primary objectives of the study are to reduce heater power and thermal gradients within the CO2 sorbent beds while minimizing channeling effects. Some of the notable changes from the ISS (International Space Station) CDRA (Carbon Dioxide Removal Assembly) to the proposed exploration system architecture include cylindrical beds, alternate sorbents and an improved heater core. Results from both 2D and 3D sorbent bed thermal models with integrated heaters are presented. The 2D sorbent bed models are used to optimize heater power and fin geometry while the 3D models address end effects in the beds for more realistic thermal gradient and heater power predictions.

  19. Comparison of Simulation and Experimental Results of Class - D Inverter Fed Induction Heater

    Directory of Open Access Journals (Sweden)

    S. Rama Reddy

    2010-10-01

    Full Text Available This research deals w ith simulation and experimentation of closed loop controlled class-D inverter fed induction heater system. This converter has reduced switching losses, stress and increased power density. The inverter system is designed and the simulation is done using Matlab. The results of simulation and experimentation are presented. The induction heater system uses embedded controller to generate driving pulses. The objective is to develop an induction heater system with minimum hardware.

  20. Thermal performance optimization of a flat plate solar air heater using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Varun; Siddhartha [Department of Mechanical Engineering, National Institute of Technology, Hamirpur 177 005 (H.P.) (India)

    2010-05-15

    Thermal performance of solar air heater is low and different techniques are adopted to increase the performance of solar air heaters, such as: fins, artificial roughness etc. In this paper an attempt has been done to optimize the thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different Reynolds number, emissivity of the plate, tilt angle and number of glass plates by using genetic algorithm. (author)

  1. Possible conservation units of the sun bear (Helarctos malayanus) in Sarawak based on variation of mtDNA control region.

    Science.gov (United States)

    Onuma, Manabu; Suzuki, Masatsugu; Ohtaishi, Noriyuki

    2006-11-01

    The mitochondrial DNA control region of the sun bear (Helarctos malayanus) was sequenced using 21 DNA samples collected from confiscated sun bears to identify conservation units, such as evolutionarily significant units and management units, in Sarawak, Borneo Island. A total of 10 haplotypes were observed, indicating the presence of at least two lineages in the sun bear population in Sarawak. Presumably, these two lineages could represent evolutionarily significant units. However, the geographical distributions of the two lineages remained unknown due to the lack of information regarding the exact capture locations of the confiscated sun bears. It is essential to elucidate the geographical distributions of these lineages in order to create a proper conservation plan for the sun bears in Sarawak. Therefore, further studies examining the haplotype distributions using DNA samples from known localities are essential.

  2. Sensitivity analysis of thermal performances of flat plate solar air heaters

    Science.gov (United States)

    Njomo, Donatien; Daguenet, Michel

    2006-10-01

    Sensitivity analysis is a mathematical tool, first developed for optimization methods, which aim is to characterize a system response through the variations of its output parameters following modifications imposed on the input parameters of the system. Such an analysis may quickly become laborious when the thermal model under consideration is complex or the number of input parameters is high. In this paper, we develop a mathematical model to analyse the heat exchanges in four different types of solar air collectors. When building this thermal model we show that for each collector, at quasi-steady state, the energy balance equations of the components of the collector cascade into a single first-order non-linear differential equation that is able to predict the thermal behaviour of the collector. Our heat transfer model clearly demonstrates the existence of an important dimensionless parameter, referred to as the thermal performance factor of the collector, that compares the useful thermal energy which can be extracted from the heater to the overall thermal losses of that collector for a given set of input parameters. A sensitivity analysis of our thermal model has been performed for the most significant input parameters such as the incident solar irradiation, the inlet fluid temperature, the air mass flow rate, the depth of the fluid channel, the number and nature of the transparent covers in order to measure the impact of each of these parameters on our model. An important result which can be drawn from this study is that the heat transfer model developed is robust enough to be used for thermal design studies of most known flat plate solar air heaters, but also of flat plate solar water collectors and linear solar concentrators.

  3. Integration issues of a plasma contactor Power Electronics Unit

    Science.gov (United States)

    Pinero, Luis R.; York, Kenneth W.; Bowers, Glen E.

    1995-06-01

    A hollow cathode-based plasma contactor is baselined on International Space Station Alpha (ISSA) for spacecraft charge control. The plasma contactor system consists of a hollow cathode assembly (HCA), a power electronics unit (PEU), and an expellant management unit (EMU). The plasma contactor has recently been required to operate in a cyclic mode to conserve xenon expellant and extend system life. Originally, a DC cathode heater converter was baselined for a continuous operation mode because only a few ignitions of the hollow cathode were expected. However, for cyclic operation, a DC heater supply can potentially result in hollow cathode heater component failure due to the DC electrostatic field. This can prevent the heater from attaining the proper cathode tip temperature for reliable ignition of the hollow cathode. To mitigate this problem, an AC cathode heater supply was therefore designed, fabricated, and installed into a modified PEU. The PEU was tested using resistive loads and then integrated with an engineering model hollow cathode to demonstrate stable steady-state operation. Integration issues such as the effect of line and load impedance on the output of the AC cathode heater supply and the characterization of the temperature profile of the heater under AC excitation were investigated.

  4. Integration issues of a plasma contactor Power Electronics Unit

    Science.gov (United States)

    Pinero, Luis R.; York, Kenneth W.; Bowers, Glen E.

    1995-01-01

    A hollow cathode-based plasma contactor is baselined on International Space Station Alpha (ISSA) for spacecraft charge control. The plasma contactor system consists of a hollow cathode assembly (HCA), a power electronics unit (PEU), and an expellant management unit (EMU). The plasma contactor has recently been required to operate in a cyclic mode to conserve xenon expellant and extend system life. Originally, a DC cathode heater converter was baselined for a continuous operation mode because only a few ignitions of the hollow cathode were expected. However, for cyclic operation, a DC heater supply can potentially result in hollow cathode heater component failure due to the DC electrostatic field. This can prevent the heater from attaining the proper cathode tip temperature for reliable ignition of the hollow cathode. To mitigate this problem, an AC cathode heater supply was therefore designed, fabricated, and installed into a modified PEU. The PEU was tested using resistive loads and then integrated with an engineering model hollow cathode to demonstrate stable steady-state operation. Integration issues such as the effect of line and load impedance on the output of the AC cathode heater supply and the characterization of the temperature profile of the heater under AC excitation were investigated.

  5. Large capacity, multi-fuel, and high temperature working fluid heaters to optimize CSP plant cost, complexity and annual generation

    Science.gov (United States)

    Peterseim, J. H.; Viscuso, L.; Hellwig, U.; McIntyre, P.

    2016-05-01

    This paper analyses the potential to optimize high temperature fluid back-up systems for concentrating solar power (CSP) plants by investigating the cost impact of component capacity and the impact of using multiple fuels on annual generation. Until now back-up heaters have been limited to 20MWth capacity but larger units have been realised in other industries. Installing larger units yields economy-of-scale benefits through improved manufacturing, optimised transport, and minimized on-site installation work. Halving the number of back-up boilers can yield cost reduction of 23% while minimizing plant complexity and on-site construction risk. However, to achieve these benefits it is important to adapt the back-up heaters to the plant's requirements (load change, capacity, minimum load, etc.) and design for manufacture, transport and assembly. Despite the fact that biomass availability is decreasing with increasing direct normal irradiance (DNI), some biomass is available in areas suitable for CSP plants. The use of these biomass resources is beneficial to maximise annual renewable energy generation, substitute natural gas, and use locally/seasonally available biomass resources that may not be used otherwise. Even small biomass quantities of only 50,000 t/a can increase the capacity factor of a 50MWe parabolic trough plant with 7h thermal energy storage from 40 to 49%. This is a valuable increase and such a concept is suitable for new plants and retrofit applications. However, similar to the capacity optimisation of back-up heaters, various design criteria have to be considered to ensure a successful project.

  6. Zoned electrical heater arranged in spaced relationship from particulate filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-11-15

    A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

  7. Thin film heater for removable volatile protecting coatings.

    Science.gov (United States)

    Karim, Abid

    2013-01-01

    Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces.

  8. Benchmark Tests for Stirling Convertor Heater Head Life Assessment Conducted

    Science.gov (United States)

    Krause, David L.; Halford, Gary R.; Bowman, Randy R.

    2004-01-01

    A new in-house test capability has been developed at the NASA Glenn Research Center, where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive testing to aid the development of analytical life prediction methodology and to experimentally aid in verification of the flight-design component's life. The new facility includes two test rigs that are performing creep testing of the SRG heater head pressure vessel test articles at design temperature and with wall stresses ranging from operating level to seven times that (see the following photograph).

  9. CVD diamond resistor as heater and temperature sensor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, G.S.; Aslam, M. [Michigan State Univ., East Lansing, MI (United States)

    1995-12-31

    Heat generation and temperature control, essential for most heater applications, require different components in a conventional system. We achieve the heat generation and temperature measurement simultaneously by using a single diamond resistor. Chemical vapor deposited (CVD) p-type diamond resistors with different dimensions were fabricated on polycrystalline diamond or oxidized Si substrates using diamond film technology compatible with integrated circuit (IC) processing. The temperature response of the resistors was characterized in the temperature range of 25 - 500{degrees}C. Power densities in access of 600 watt/in{sup 2} were achieved.

  10. Integral finned heater and cooler for stirling engines

    Science.gov (United States)

    Corey, John A.

    1984-01-01

    A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

  11. Applicability of Pulse Pressure Variation during Unstable Hemodynamic Events in the Intensive Care Unit: A Five-Day Prospective Multicenter Study

    Directory of Open Access Journals (Sweden)

    Bertrand Delannoy

    2016-01-01

    Full Text Available Pulse pressure variation can predict fluid responsiveness in strict applicability conditions. The purpose of this study was to describe the clinical applicability of pulse pressure variation during episodes of patient hemodynamic instability in the intensive care unit. We conducted a five-day, seven-center prospective study that included patients presenting with an unstable hemodynamic event. The six predefined inclusion criteria for pulse pressure variation applicability were as follows: mechanical ventilation, tidal volume >7 mL/kg, sinus rhythm, no spontaneous breath, heart rate/respiratory rate ratio >3.6, absence of right ventricular dysfunction, or severe valvulopathy. Seventy-three patients presented at least one unstable hemodynamic event, with a total of 163 unstable hemodynamic events. The six predefined criteria for the applicability of pulse pressure variation were completely present in only 7% of these. This data indicates that PPV should only be used alongside a strong understanding of the relevant physiology and applicability criteria. Although these exclusion criteria appear to be profound, they likely represent an absolute contraindication of use for only a minority of critical care patients.

  12. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  13. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-28

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  14. Space Heaters, Computers, Cell Phone Chargers: How Plugged In AreCommercial Buildings?

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, Marla; Webber, Carrie; Brown, Richard; Busch, John; Pinckard, Margaret; Roberson, Judy

    2007-02-28

    Evidenceof electric plug loads in commercial buildings isvisible everyday: space heaters, portable fans, and the IT technician'stwo monitors connected to one PC. The Energy Information Administrationestimates that office and miscellaneous equipment together will consume2.18 quads in 2006, nearly 50 percent of U.S. commercial electricity use.Although the importance of commercial plug loads is documented, its verynature (diverse product types, products not installed when buildinginitially constructed, and products often hidden in closets) makes itdifficult to accurately count and categorize the end use.We auditedsixteen buildings in three cities (San Francisco, Atlanta, Pittsburgh)including office, medical and education building types. We inventoriedthe number and types of office and miscellaneous electric equipment aswell as estimated total energy consumption due to these product types. Intotal, we audited approximately 4,000 units of office equipment and 6,000units of miscellaneous equipment and covered a diverse range of productsranging from electric pencil sharpeners with a unit energy consumption(UEC) of 1 kWh/yr to a kiln with a UEC of 7,000 kWh/yr. Our paperpresents a summary of the density and type of plug load equipment foundas well as the estimated total energy consumption of the equipment.Additionally, we present equipment trends observed and provide insightsto how policy makers can target energy efficiency for this growing enduse.

  15. Modeling the longitudinal variation in wood specific gravity of planted loblolly pine (Pinus taeda) in the United States

    Science.gov (United States)

    F. Antony; L. R. Schimleck; R. F. Daniels; Alexander Clark; D. B. Hall

    2010-01-01

    Loblolly pine (Pinus taeda L.) is a major plantation species grown in the southern United States, producing wood having a multitude of uses including pulp and lumber production. Specific gravity (SG) is an important property used to measure the quality of wood produced, and it varies regionally and within the tree with height and radius. SG at different height levels...

  16. High-performance, bare silver nanowire network transparent heaters.

    Science.gov (United States)

    Ergun, Orcun; Coskun, Sahin; Yusufoglu, Yusuf; Unalan, Husnu Emrah

    2016-11-04

    Silver nanowire (Ag NW) networks are one of the most promising candidates for the replacement of indium tin oxide (ITO) thin films in many different applications. Recently, Ag-NW-based transparent heaters (THs) showed excellent heating performance. In order to overcome the instability issues of Ag NW networks, researchers have offered different hybrid structures. However, these approaches not only require extra processing, but also decrease the optical performance of Ag NW networks. So, it is important to investigate and determine the thermal performance limits of bare-Ag-NW-network-based THs. Herein, we report on the effect of NW density, contact geometry, applied bias, flexing and incremental bias application on the TH performance of Ag NW networks. Ag-NW-network-based THs with a sheet resistance and percentage transmittance of 4.3 Ω sq(-1) and 83.3%, respectively, and a NW density of 1.6 NW μm(-2) reached a maximum temperature of 275 °C under incremental bias application (5 V maximum). With this performance, our results provide a different perspective on bare-Ag-NW-network-based transparent heaters.

  17. Evaluation of Tube Wall Thickness of Feed Water Heater

    Science.gov (United States)

    Uchikura, Takahisa; Morisaki, Koichi; Hamada, Seiichi

    With regard to the high pressure (HP) feed water heater of thermal power plant at Tokyo Electric Power Company (TEPCO) sites, inspection of feed water (FW) tubes wall thickness are conducted whenever required such that frequent tube leak occurs. As a standard inspection methodology, FW heater is disassembled during planned outage, tube wall thickness is measured by the ultrasonic pulse techique (UT), then plugs are installed at the both ends of FW tube if its measured wall thickness is found below calculated threshold. However, the root causes of wall thinning of FW tube are various such as erosion and corrosion, based on wall thinning condition, the above threshold is not applied but utilizing the other technically well-grounded evaluation method is sometimes more rational. Therefore, TEPCO classified wall-thinning condition based on inspection data and established technically well-grounded and rational evaluation methodologies of FW tube wall thickness to suite each wall thinning condition. Moreover, with recent improvement of inspection technique, technology enabled faster, larger amount, and more accurate data acquisition, TEPCO has developed the systematized evaluation methodology that can transact data acquisition and evaluation simultaneously. This article introduces the logic of evaluation methods and examined algorithms to make them systematized.

  18. Eleana near-surface heater experiment final report

    Energy Technology Data Exchange (ETDEWEB)

    Lappin, A R; Thomas, R K; McVey, D F

    1981-04-01

    This report summarizes the results of a near-surface heater experiment operated at a depth of 23 m in argillite within the Eleana Formation on the Nevada Test Site (NTS). The test geometrically simulated emplacement of a single canister of High-Level Waste (HLW) and was operated at a power level of 2.5 kW for 21 days, followed by 3.8 kW to 250 days, when the power was turned off. Below 85 to 100{sup 0}C, there was good agreement between modeled and measured thermal results in the rock and in the emplacement hole, except for transient transport of water in the heater hole. Above 100{sup 0}C, modeled and measured thermal results increasingly diverged, indicating that the in-situ rock-mass thermal conductivity decreased as a result of dehydration more than expected on the basis of matrix properties. Correlation of thermomechanical modeling and field results suggests that this decrease was caused by strong coupling of thermal and mechanical behavior of the argillite at elevated temperatures. No hole-wall decrepitation was observed in the experiment; this fact and the codrrelation of modeled and measured results at lower temperatures indicate that there is no a priori reason to eliminate argillaceous rocks from further consideration as a host rock for nuclear wastes.

  19. A micro solar heater for portable energy generation

    Science.gov (United States)

    Zimmerman, Raúl; Morrison, Graham; The, Owen; Rosengarten, Gary

    2007-12-01

    This study presents a new concept that combines microtechnology with solar thermal energy to provide a free portable energy source. A water-methanol mixture flows through an array of parallel microchannels which are fabricated into a silicon matrix using conventional micro-fabrication techniques. A vacuum layer is interposed between the channels and the external surface to thermally insulate the channels from the ambient temperature. A selective coating is deposited on one of the vacuum walls to absorb the short wavelength incoming radiation and reduce the long wavelength radiation, hence reducing the heat losses. A geometry and material optimization is still being developed in order to obtain the highest possible efficiency for the micro-heater, while keeping a low pressure drop in the micro-channels. The methanol outlet temperature is predicted to be higher than 250°C. This temperature is required for hydrogen production in a methanol reforming micro-reactor. Therefore, it is envisaged that the micro-solar heater will supply the thermal energy needed for hydrogen generation, that can later be used as fuel for microfuel cells. Both technologies can be integrated in a portable device.

  20. 46 CFR 52.01-35 - Auxiliary, donkey, fired thermal fluid heater, and heating boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Auxiliary, donkey, fired thermal fluid heater, and... requirements for miscellaneous boiler types, such as donkey, fired thermal fluid heater, heating boiler, etc... (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-35 Auxiliary, donkey, fired...

  1. CFD Study of Fluid Flow in an All-glass Evacuated Tube Solar Water Heater

    DEFF Research Database (Denmark)

    Ai, Ning; Fan, Jianhua; Li, Yumin

    2008-01-01

    Abstract: The all-glass evacuated tube solar water heater is one of the most widely used solar thermal technologies. The aim of the paper is to investigate fluid flow in the solar water heater by means of computational fluid dynamics (CFD). The investigation was carried out with a focus...

  2. Demonstration of a heat pump water heater. Volume 3. Design report

    Energy Technology Data Exchange (ETDEWEB)

    Sloane, B.D.; Krise, R.C.; Kent, D.D.

    1979-12-01

    Work performed during the pilot run manufacturing and laboratory testing stages of a heat pump water heater for residential installations is described. A general description of the heat pump water heater is provided, as are detailed discussions of individual components. Also included is a description of the pilot run manufacturing facility and experience, laboratory operations, and laboratory test data.

  3. Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

  4. Tankless water heaters fill the bill at fast-food restaurants

    Energy Technology Data Exchange (ETDEWEB)

    1988-02-01

    This article explains why Kentucky Fried Chicken has installed a PH-24 water heater. The tankless water heater meets the restaurant's criteria for space spacing, flow rates, certification and availability, and money saving efficiency. This article describes the system and its advantages.

  5. 75 FR 21981 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

    Science.gov (United States)

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY 10 CFR Part 430 RIN 1904-AA90 Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters Correction In rule document 2010-7611 beginning...

  6. Spatial-temporal Variation Characteristics of Grain Yield per Unit Area and its Balanced Increasing Potential in China

    Directory of Open Access Journals (Sweden)

    Liu Yu

    2015-03-01

    Full Text Available The aim of this study is to provide assistance decision for grain yield in China, which can provide basis for reasonable layout of grain production project. Based on the statistical data of 2301 counties in China, using spatial autocorrelation analysis method, spatial changes of grain yield per unit area at county level in China during 1990-2010 were discussed and then the increase potential of grain yield per hectare and total yield at regional scale were calculated. The results showed that: (1 Grain yield per unit area at county level showed the evident pattern “High in the northern while low in the southern” and “High in the eastern and western while low in the middle”; The average grain yield per hectare increased by 1040.74 kg/hm2 during 1990-2010 and the increment of grain yield per unit area descended from North to South at county level. (2 Grain yield per unit area at county level in China had a strong spatial autocorrelation. The counties with "High-High" and "Low-Low" correlation were the majority. Counties with significant "High-High" correlation in 2010 were mostly located in plain area, while counties with significant "Low-Low" correlation were mainly distributed in Hengduan Mountainous Area, Inner Mongolia steppe Area, etc. (3 Two thousand three hundred and one counties were divided into 41 first-grade regions and 115 sec-grade regions according to the coupled conditions of cultivation system regionalization and LISA cluster map. The total potential output of China was 1.77×108 tons.

  7. Analysis of Uncertainties in Protection Heater Delay Time Measurements and Simulations in Nb$_{3}$Sn High-Field Accelerator Magnets

    CERN Document Server

    Salmi, Tiina; Marchevsky, Maxim; Bajas, Hugo; Felice, Helene; Stenvall, Antti

    2015-01-01

    The quench protection of superconducting high-field accelerator magnets is presently based on protection heaters, which are activated upon quench detection to accelerate the quench propagation within the winding. Estimations of the heater delay to initiate a normal zone in the coil are essential for the protection design. During the development of Nb3Sn magnets for the LHC luminosity upgrade, protection heater delays have been measured in several experiments, and a new computational tool CoHDA (Code for Heater Delay Analysis) has been developed for heater design. Several computational quench analyses suggest that the efficiency of the present heater technology is on the borderline of protecting the magnets. Quantifying the inevitable uncertainties related to the measured and simulated delays is therefore of pivotal importance. In this paper, we analyze the uncertainties in the heater delay measurements and simulations using data from five impregnated high-field Nb3Sn magnets with different heater geometries. ...

  8. High thermal performance of SnO2:F thin transparent heaters with scattered metal nanodots.

    Science.gov (United States)

    Hudaya, Chairul; Jeon, Bup Ju; Lee, Joong Kee

    2015-01-14

    Facile production and novel transparent heaters consisting of fluorine-doped tin oxide (SnO2:F or FTO) thin films covered with three different scattered metal nanodots (Cr-nd, NiCr-nd and Ni-nd) prepared by plasma-enhanced sputtering system and electron cyclotron resonance-metal organic chemical vapor deposition are investigated. The heaters exhibit excellent optical transmittances of over 85% and superior saturated temperatures of more than 80 °C when a relatively low 12 V DC is supplied. The scattered metal nanodots FTO heaters successfully improve the specific power of bare FTO heater by 21, 15, and 12% for NiCr-nd FTO, Cr-nd FTO, and Ni-nd FTO, respectively. These results reveal that the FTO transparent heaters with scattered metal nanodots are the suitable heating materials that can be applied for various functional devices.

  9. Evaluation and certification of heater assemblies developed for thermal vacuum acceptance testing

    Science.gov (United States)

    Allen, J. E.

    1986-01-01

    Preparation of Rockwell International's Thermal Vacuum Chamber for acceptance testing of a mass produced satellite required the development of unique quartz lamp and hot wire heater assemblies. Testing performed on the basic elements of these heaters is described, as is the final testing done to certify that the heater assemblies meet the thermal requirements for acceptance testing. The methods and procedures of thermal mapping used during the development and final certification of these heater assemblies are presented. The absence of a definitive standard for determining flux distribution and heating boundaries for heaters of this type required the development of a test plan incorporating several thermal mapping techniques. These techniques include the development of heat flux using a multiple calorimeter array for both vacuum and ambient test conditions, and a photographic method for detecting heating boundaries. The test plan and thermal mapping techniques are discussed.

  10. Protection Heater Design Validation for the LARP Magnets Using Thermal Imaging

    CERN Document Server

    Marchevsky, M; Cheng, D W; Felice, H; Sabbi, G; Salmi, T; Stenvall, A; Chlachidze, G; Ambrosio, G; Ferracin, P; Izquierdo Bermudez, S; Perez, J C; Todesco, E

    2016-01-01

    Protection heaters are essential elements of a quench protection scheme for high-field accelerator magnets. Various heater designs fabricated by LARP and CERN have been already tested in the LARP high-field quadrupole HQ and presently being built into the coils of the high-field quadrupole MQXF. In order to compare the heat flow characteristics and thermal diffusion timescales of different heater designs, we powered heaters of two different geometries in ambient conditions and imaged the resulting thermal distributions using a high-sensitivity thermal video camera. We observed a peculiar spatial periodicity in the temperature distribution maps potentially linked to the structure of the underlying cable. Two-dimensional numerical simulation of heat diffusion and spatial heat distribution have been conducted, and the results of simulation and experiment have been compared. Imaging revealed hot spots due to a current concentration around high curvature points of heater strip of varying cross sections and visuali...

  11. Occurrence, temporal variation, and estrogenic burden of five parabens in sewage sludge collected across the United States.

    Science.gov (United States)

    Chen, Jing; Pycke, Benny F G; Brownawell, Bruce J; Kinney, Chad A; Furlong, Edward T; Kolpin, Dana W; Halden, Rolf U

    2017-03-24

    Five parabens used as preservatives in pharmaceuticals and personal care products (PPCPs) were measured in sewage sludges collected at 14 U.S. wastewater treatment plants (WWTPs) located in nine states. Detected concentration ranges (ng/g, dry weight) and frequencies were as follows: methyl paraben (15.9 to 203.0; 100%), propyl paraben (0.5 to 7.7; 100%), ethyl paraben (paraben (paraben (parabens detected in sewage sludge (ranging from 10.1 to 500.1pg/kg 17β-estradiol equivalents) was insignificant when compared to the 10(6)-times higher value calculated for natural estrogens reported in the literature to occur in sewage sludge. Temporal monitoring at one WWTP provided insights into temporal and seasonal variations in paraben concentrations. This is the first report on the occurrence of five parabens in sewage sludges from across the U.S., and internationally, the first on temporal variations of paraben levels in sewage sludge. Study results will help to inform the risk assessment of sewage sludge destined for land application (biosolids).

  12. 10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

    Science.gov (United States)

    2010-01-01

    ... Instantaneous Water Heaters and Hot Water Supply Boilers* Thermal Efficiency ANSI Z21.10.3-1998, § 2.9** A. For... Instantaneous Water Heaters and Hot Water Supply Boilers* Thermal Efficiency ANSI Z21.10.3-1998, § 2.9** (2) Oil...) Assume that the thermal efficiency (Et) of electric water heaters with immersed heating elements is...

  13. Analysis of thermal stresses in horizontal delivery water heaters

    Science.gov (United States)

    Bilan, A. V.; Plotnikov, P. N.

    2016-11-01

    Analysis of thermal stresses in tubes and a compensator, taking into account water heating in each heater bunch and temperature at which its mounting is implemented, and of stresses on pressure is presented. The 3D-model of the horizontal delivery water heater of PSG-4900-0.3-1.14 type is used. The tube plate is represented as the 3D-body with 6863 holes with offset center of the perforated area, the steam space shell is represented as a cylindrical casing, the bottoms of water chambers are considered as elliptical casings, the four-lens compensator is represented in the form of toroidal casings, and the tubes are considered as beams operating in tensile-compression and bending in two planes. Calculations were carried out for different temperatures of superheated steam and a steam space shell, respectively, as well as designs with compensator and without it. Various temperature values of the tubes on the passes were calculated and set. The studies were carried out taking into account nonaxis-symmetrical spacing the tube plate and compensator deformation. The calculation results of tensile-compression stresses in the tubes are presented. Furthermore, the central tubes experience compressive stresses, whose maximal values take place on the border between the tubes of the fourth and of the first passes. For its decrease, it is recommended to increase the distance between the tubes of these passes. The tension stresses in the peripheral tubes are the maximal stresses. To reduce the stresses and, therefore, increase service life of the delivery water heater at using wet or superheated (not more than by 30-50°C) steam in it (the larger value refers to the brass tubes and the water pressure of 1.6-2.5 MPa), it is necessary to recommend the noncompensatory design at using the steam superheated by more than 30-50°C (at Ural Turbine Works, it is the turbines of T-250/300-23.5 and T-113/145-12.4 types with intermediate superheating) and to recommend the installation of the

  14. Words Can Be Deceiving: A Review of Variation Among Legally Effective Medical Marijuana Laws in the United States.

    Science.gov (United States)

    Pacula, Rosalie Liccardo; Hunt, Priscillia; Boustead, Anne

    2014-12-01

    When voters in two US states approved the recreational use of marijuana in 2012, public debates for how best to promote and protect public health and safety started drawing implications from states' medical marijuana laws. However, many of the discussions were simplified to the notion that states either have a medical marijuana law or do not; little reference was made to the fact that legal provisions differ across states. This study seeks to clarify the characteristics of medical marijuana laws in place since 1990 that are most relevant to consumers/patients and categorizes those aspects most likely to affect the prevalence of use, and consequently the intensity of public health and welfare effects. Evidence shows treating medical marijuana laws as homogeneous across states is misleading and does not reflect the reality of medical marijuana lawmaking. This variation likely has implications for use and health outcomes, and thus states' public health.

  15. Variation in neoadjuvant chemotherapy utilization for epithelial ovarian cancer at high volume hospitals in the United States and associated survival.

    Science.gov (United States)

    Barber, Emma L; Dusetzina, Stacie B; Stitzenberg, Karyn B; Rossi, Emma C; Gehrig, Paola A; Boggess, John F; Garrett, Joanne M

    2017-06-01

    To estimate variation in the use of neoadjuvant chemotherapy by high volume hospitals and to determine the association between hospital utilization of neoadjuvant chemotherapy and survival. We identified incident cases of stage IIIC or IV epithelial ovarian cancer in the National Cancer Database from 2006 to 2012. Inclusion criteria were treatment at a high volume hospital (>20 cases/year) and treatment with both chemotherapy and surgery. A logistic regression model was used to predict receipt of neoadjuvant chemotherapy based on case-mix predictors (age, comorbidities, stage etc). Hospitals were categorized by the observed-to-expected ratio for neoadjuvant chemotherapy use as low, average, or high utilization hospitals. Survival analysis was performed. We identified 11,574 patients treated at 55 high volume hospitals. Neoadjuvant chemotherapy was used for 21.6% (n=2494) of patients and use varied widely by hospital, from 5%-55%. High utilization hospitals (n=1910, 10 hospitals) had a median neoadjuvant chemotherapy rate of 39% (range 23-55%), while low utilization hospitals (n=2671, 14 hospitals) had a median rate of 10% (range 5-17%). For all ovarian cancer patients adjusting for clinical and socio-demographic factors, treatment at a hospital with average or high neoadjuvant chemotherapy utilization was associated with a decreased rate of death compared to treatment at a low utilization hospital (HR 0.90 95% CI 0.83-0.97 and HR 0.85 95% CI 0.75-0.95). Wide variation exists in the utilization of neoadjuvant chemotherapy to treat stage IIIC and IV epithelial ovarian cancer even among high volume hospitals. Patients treated at hospitals with low rates of neoadjuvant chemotherapy utilization experience decreased survival. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Controlled cellular fusion using optically trapped plasmonic nano-heaters

    Science.gov (United States)

    Bahadori, Azra; Lund, Andreas R.; Semsey, Szabolcs; Oddershede, Lene B.; Bendix, Poul M.

    2016-09-01

    Optically trapped plasmonic nano-heaters are used to mediate efficient and controlled fusion of biological membranes. The fusion method is demonstrated by optically trapping plasmonic nanoparticles located in between vesicle membranes leading to rapid lipid and content mixing. As an interesting application we show how direct control over fusion can be used for studying diffusion of peripheral membrane proteins and their interactions with membranes and for studying protein reactions. Membrane proteins encapsulated in an inert vesicle can be transferred to a vesicle composed of negative lipids by optically induced fusion. Mixing of the two membranes results in a fused vesicle with a high affinity for the protein and we observe immediate membrane tubulation due to the activity of the protein. Fusion of distinct membrane compartments also has applications in small scale chemistry for realizing pico-liter reactions and offers many exciting applications within biology which are discussed here.

  17. Thermoacoustic Stirling Heat Pump Working as a Heater

    Science.gov (United States)

    Bassem, Mohamed Mehdi; Ueda, Yuki; Akisawa, Atsushi

    2011-10-01

    A prototype thermoacoustic heat pump working as a heater was demonstrated. The heat pump was composed of an acoustic driver, a branched tube, and a looped tube containing a regenerator; the looped tube was connected to the acoustic driver via the branched tube, and the regenerator consisted of many narrow flow channels. The measurement results of the acoustic impedance inside the looped tube indicated that the energy conversion of the acoustic power flow into the acoustic heat flow in the regenerator occurred through the inherently efficient Stirling cycle. Moreover, the heat pump generated a hot temperature of 370 °C, corresponding to a temperature lift along the regenerator of 340 °C.

  18. THE HEAT AND FLUID FLOW ANALYSIS FOR WATER HEATER

    Directory of Open Access Journals (Sweden)

    Chien-Nan Lin

    2011-01-01

    Full Text Available In this paper, the heat transfer and fluid flow are studied for the water heater of RV cars, in which the hot water is heated by the combustion energy of liquefied petroleum gases. Three types of combustion tubes are performed in this investigation, which are circular tube, elliptic tube and elliptic tube with screwed wire inserted. The heat transfer performances of numerical simulation results are compared with those of the experimental works; they are in good trend agreement. The elliptic combustion tube performs better than the circular one, which indicates the average 7% energy saving for the elliptic combustion tube and 12% energy saving for the elliptic combustion tube with screwed wire under static heating.

  19. Results of MPBX studies at the single heater test

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S. C.,LLNL

    1997-10-01

    We have developed an extensometer for measurement of distance and displacements in a geologic repository for high-level nuclear waste. This is an optical extensometer that measures distance using a modulated laser beam. In this design, reflecting targets are placed at desired measurement locations, and distance between each target and an optical head are measured repeatedly using the modulated laser beam. Moreover, all electronic and moving parts are located outside of the hostile or difficult environment as the optical head is connected to the laser, switching and signal analysis hardware using optical fibers. A reference beam is utilized to provide direct correction of system behavior. `Be system also - utilizes movable reflective anchors that can be repositioned if desired. We have installed the system in the Single Heater Test being conducted in Alcove 5 of the Exploratory Studies Facility at Yucca Mountain, and report preliminary results.

  20. Thin Film Heater for Removable Volatile Protecting Coatings

    Directory of Open Access Journals (Sweden)

    Abid Karim

    2013-01-01

    Full Text Available Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces.

  1. Modelling of Closed Loop Class E Inverter Based Induction Heater

    Directory of Open Access Journals (Sweden)

    S. Arumugam

    2011-01-01

    Full Text Available This study presents simulation of class E inverter based induction heater system using simulink. DC is converted into high frequency AC using class E inverter. This high frequency AC is used for induction heating. Closed loop systems are modeled and they are simulated using Mat lab Simulink.The results of closed loop systems are presented. The proposed amplifier with two series-parallel resonant load networks will allow sinusoidal output voltage to be achieved by associating with the positive and negative quasi-sinusoidal waveforms. The complementarily activated configuration will provide continuous high-ripple-frequency inputcurrent waveforms; this approach significantly reduces electromagnetic interference and requires very little filtering. With the symmetry of the push-pull Class-E Circuit, there is the additional benefit that the even harmonics are suppressed at the load, and thus there are fewer harmonic distortions.

  2. Constant delivery temperature solar water heater - an integrated approach

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. [C.A.S. Indian Institute of Technology, New Delhi (India); Kumar, N. [D.C.E. Muzaffarpur Institute of Technology, Bihar (India)

    1997-05-01

    An integrated model of a constant delivery temperature solar water heat-cum-active regenerative distillation system has been developed. The water used for the regenerative effect in the distiller of the proposed system is subsequently fed to the basin-cum-storage tank of the still through the heat exchanger (connected to the collector). The model varies the water mass flow rate in order to maintain a constant outlet temperature. With minor modifications in the solar water heater, the extra energy stored in the water mass due to non-utilization of capacity and/or non-linear utilization of capacity can be efficiently utilized for distillation purposes. In this process, the latent heat of vaporization is used for preheating the inlet water supply to the heat exchanger. The effect of insulation on maintaining the hot water temperature and distillate output is also presented. (Author)

  3. FEM Optimal Design of Wind Energy-based Heater

    Directory of Open Access Journals (Sweden)

    Tiberiu Tudorache

    2009-07-01

    Full Text Available This paper deals with the finite element based optimal design of a wind energybased heater. The proposed device ensures the conversion of the wind kinetic energy intoheat by means of Joule effect of eddy currents induced in the wall of a tubular stator due tothe rotating magnetic field produced by rotor permanent magnets. The transientelectromagnetic field problem associated to the operation of the device is solved using a2D finite element approach based on vector potential formulation. A simplified method forthe 2D heat transfer analysis of the device is also proposed. The influence of stator wallmaterial and thickness, number of poles, the airgap thickness and the geometricalparameters of the permanent magnets is analyzed in the aim of optimizing the studiedheater.

  4. Generation of Acoustic Gravity Waves by Periodic Radio Transmissions from a High-Power Ionospheric Heater

    Science.gov (United States)

    Frolov, Vladimir; Chernogor, Leonid; Rozumenko, Victor

    the F _{_2} layer critical frequency. High-power periodic radio transmissions are capable of enhancing/damping natural wave perturbations generated by the solar terminator. 3. The study has demonstrated that the generation and propagation of AGWs with periods close to the natural oscillation periods of the atmosphere is possible. The duration of AGW oscillation trains does not dependent on the duration of turn-on/-off trains, but it is determined by changes in the current state of the atmosphere-ionosphere-magnetosphere system in general. The period of the AGW oscillation trains is determined by the period or semi-period of the pumping. It means that the mechanism of AGW generation in this case is distinct from the agreed-upon mechanism developed earlier. The AGWs, whose periods are 5 - 10% greater than the Brunt-Vaisala period, exhibit group velocities less than the speed of sound that is of about 80 - 160 m/s. They induce electron density perturbations of about 1.1 - 1.5%. The AGW generation has the following features. When the effective radiated power (ERP) is 50 MW or less, AGWs are not detected; they are reliably observed when the ERP is equal or larger than about 100 MW. Geomagnetic storms play a dual role in the AGW generation because they: (i) increase amplitudes of AGWs with 4 - 6-min and 8 - 12-min periods and (ii) yet enhance background oscillations. The latter hampers the identification of the HF-induced oscillations. Moderate magnetic storms do not markedly exert an influence on the amplitudes of oscillations with 13 - 17-min periods. 4. The quasi-periodic variations in the horizontal components of the geomagnetic field with 8 - 12-min periods become observable near Kharkiv 35 - 45 min after the beginning of pumping. Their speeds are 355 - 460 m/s, and they form trains 40 - 90 min in duration when the [5-min on, 5-min off] or [10-min on, 10-min off] heater timing is used. The 12 - 18-min period variations become observable 35 - 45 min after the beginning

  5. Three-Dimensional Printable High-Temperature and High-Rate Heaters.

    Science.gov (United States)

    Yao, Yonggang; Fu, Kun Kelvin; Yan, Chaoyi; Dai, Jiaqi; Chen, Yanan; Wang, Yibo; Zhang, Bilun; Hitz, Emily; Hu, Liangbing

    2016-05-24

    High temperature heaters are ubiquitously used in materials synthesis and device processing. In this work, we developed three-dimensional (3D) printed reduced graphene oxide (RGO)-based heaters to function as high-performance thermal supply with high temperature and ultrafast heating rate. Compared with other heating sources, such as furnace, laser, and infrared radiation, the 3D printed heaters demonstrated in this work have the following distinct advantages: (1) the RGO based heater can operate at high temperature up to 3000 K because of using the high temperature-sustainable carbon material; (2) the heater temperature can be ramped up and down with extremely fast rates, up to ∼20 000 K/second; (3) heaters with different shapes can be directly printed with small sizes and onto different substrates to enable heating anywhere. The 3D printable RGO heaters can be applied to a wide range of nanomanufacturing when precise temperature control in time, placement, and the ramping rate are important.

  6. Three-dimensional temperature field in a line-heater embedded by a spiral electric resistor

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, S.Y.; Wei, P.S.; Wang, Z.P. [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, 70, Lien-hai Road, Kaohsiung 804, Taiwan (China)

    2006-06-15

    In this study, three-dimensional temperature fields induced by AC and DC through a spiral electric resistor in a line-heater are numerically investigated. Electric heaters have been widely found, for example, in houses as dryers, stoves, and water heaters, and in industrial and research institutions as elements of equipments. The line-heater in the present model is realistically considered to have multiple regions composed of a spiral electric resistor, electrically insulated region, covering outer layer, and two terminal pins with distinct thermal and electrical properties. Solving unsteady three-dimensional heat conduction equations in distinct regions, the surface temperatures predicted as a function of time in this model are confirmed by the measured data. The calculated results quantitatively show that high surface temperatures of the heater can be reached by increasing dimensionless joule heat parameter, radius of the spiral electric resistor or pins, thermal diffusivity of the insulation region, and decreasing Biot number and radius of insulation region. The effects of the pins on surface temperature are also studied. Aside from showing that DC produces higher temperature than AC, the results indicate that the effects of current frequency on temperature fields are insignificant. The findings can be generalized to a curved heater, because any local location can be considered as a small line-segment. The present work provides general and quantitative data valuable for designing an efficient heater/furnace. [Author].

  7. Update on the Design and Development of a TEG Cogenerator Device Integrated into Self-Standing Gas Heaters

    Science.gov (United States)

    Codecasa, Matteo Paolo; Fanciulli, Carlo; Gaddi, Roberto; Gomez-Paz, Francisco; Passaretti, Francesca

    2013-07-01

    Heating by gas combustion is widespread in residential and industrial environments, through the use of different types of systems and plants. A relevant case is that of gas stoves, where the heat-radiating unit operates autonomously with local gas feeding. A thermoelectric generator (TEG) can be integrated within this type of autonomous gas heater, for local production of electric power, so that devices requiring electric power can be added, where desired, without the need for any connection to the electrical grid. This approach can also lead to easier installation and operation, and eventually increases the overall efficiency. Following the development plan presented in a previous report, a new prototype of an autonomous gas heater for outdoor use has been implemented through the integration of an improved TEG device with a simple and robust design, which can be easily operated by the end-user. A small amount of heat is withdrawn and converted into electricity by the TEG, providing self-sustaining operation and, moreover, powering additional functions such as high-efficiency light-emitting diode lighting.

  8. A variation on forced migration: Wilhelm Peters (Prussia via Britain to Turkey) and Muzafer Sherif (Turkey to the United States).

    Science.gov (United States)

    Russell, Gül

    2016-01-01

    In 1933 the Turkish Republic formally offered university positions to 30 German-speaking academics who were dismissed with the coming to power of the National Socialist Government. That initial number went up to 56 with the inclusion of the technical assistants. By 1948 the estimated total had increased to 199. Given renewable five-year contracts with salaries substantially higher than their Turkish counterparts, the foreign émigrés were to implement the westernization program of higher education. The ten year-old secular Turkish Republic's extensive social reforms had encompassed the adoption of the Latin alphabet, and equal rights for women, removing gender bias in hiring. Such a high concentration of émigré academics in one institution, "the highest anywhere in the world," provides a unique opportunity to study a subject which has been neglected. In this article two cases in psychology will be examined: Wilhelm Peters (1880-1963), who came, via Britain, to Istanbul in 1936 from the University of Jena in Germany, and Muzafer Sherif (1906-1988) who went to the United States from Ankara University in 1945. The purpose of the comparative analysis is to identify the features that are specific to the German experience, and those that are shared and underlie translocation in science within the multifaceted complexity of the process of forced migration.

  9. Variations in hydrostratigraphy and groundwater quality between major geomorphic units of the Western Ganges Delta plain, SW Bangladesh

    Science.gov (United States)

    Mahmud, Md. Ilias; Sultana, Sarmin; Hasan, M. Aziz; Ahmed, Kazi Matin

    2017-06-01

    Relationships among geomorphology, hydrostratigraphy, and groundwater quality with special emphasis on arsenic and salinity have been analyzed in the Bangladesh part of the Western Ganges Delta (WGD). On the basis of the presence of characteristic geomorphic features, the study area is divided into two geomorphic units: fluvial deltaic plain (FDP) and fluvio-tidal deltaic plain (FTDP). Lithostratigraphic sections demonstrate that FDP is composed predominately of sandy material whereas FTDP is characterized by alternation of sand and clay/silty clay material. Hydrostratigraphically, FDP is characterized as a single aquifer system, whereas FTDP is a complex multi-aquifer system. Spatial distributions of arsenic concentrations in groundwater reveal that elevated arsenic (>0.01 mg/l) occurs mostly in the FDP. Occurrences of high arsenic in deeper part of the aquifer system (>100 m) in the FDP, particularly in the south-western part, is probably due to the absence of any prominent impermeable layer between the shallow and deeper part of the aquifer system. Distributions of chloride concentrations show an increasing trend in groundwater salinity from north to south, i.e., from FDP to FTDP.

  10. Experimental study of heat transfer enhancement in solar air heater with different angle of attack of V-down continuous ribs

    Science.gov (United States)

    Istanto, Tri; Danardono, Dominicus; Yaningsih, Indri; Wijayanta, Agung Tri

    2016-06-01

    In this paper, an experimental study on the effect of angle attack in V-down continuous ribs on heat transfer and friction factor in an artificially roughened air heater duct is presented. The electric heater with a constant heat flux as a simulation of the indoor testing solar air heater is used to heat the roughened part of rectangular duct while other parts were insulated. The system and operating conditions were used to decide the range of parameters for the study. The ratio of the width to height of the duct (W/H) was 12, the relative roughness pitch (p/e) was 10, the relative roughness height (e/Dh) was 0.033 and the angle of attack of flow (α) was 30-80°. The air flow rate corresponded to Reynolds number between 3500 -10,000. The result of heat transfer and friction factor had been compared to those for smooth duct under similar flow and thermal boundary condition. The thermo-hydraulic performance also had been considered. As a result, the maximum enhancement of Nusselt number (Nu) and friction factor(f) were 2.34 and 2.45 times, respectively. For each variation of angle attack of flow, the thermo-hydraulic performance has been compared and the result shows that a V-down continuous rib with the angle of attack of flow as 60° gave the best thermo-hydraulic performance.

  11. Double-diffusive natural convection of Cu-water nanofluid in a window shaped cavity containing multiple obstacles with a heater on bottom wall

    Science.gov (United States)

    Chowdhury, Raju; Parvin, Salma; Khan, Md. Abdul Hakim

    2017-06-01

    In the present study, natural convective heat and mass transfer and fluid flow inside a window shaped cavity filled with Cu-water nanofluid and containing multiple obstacles with a finite size heater placed in its horizontal wall is numerically investigated. Sinusoidal temperature distribution is maintained by the heater. The left and right inclined walls of the cavity are maintained at a relatively low temperature while the vertical walls are insulated. The governing equations are transformed to the dimensionless form and solved numerically using Galerkin weighted residual technique of finite element method. The influence of pertinent parameters such as thermal Rayleigh number, location of the heater and solid volume fraction of nanoparticles on the heat and mass transfer and fluid flow is studied. The results are obtained in terms of streamlines, isotherms, isoconcentrations, average Sherwood number and average Nueeslt number for the considered parameters and it is observed that the flow pattern, temperature and concentration fields are affected by the variation of the mentioned parameters.

  12. The 1997-98 El Nino Event and Related Wintertime Lightning Variations in the Southeastern United States

    Science.gov (United States)

    Goodman, S. J.; Buechler, D. E.; Knupp, K.; Driscoll, K.; McCaul, E. W., Jr.

    2000-01-01

    The El Nino Southern Oscillation (ENSO) is a climate anomaly responsible for worldwide weather impacts ranging from droughts to floods. In the United States, warm episode years are known to produce above normal rainfall along the Southeast U.S. Gulf Coast and into the Gulf of Mexico, with the greatest response observed in the October-March period of the warm episode year. The 1997-98 warm episode is notable for being the strongest event since 198283. With the recent launch of a lightning sensor on NASA's Tropical Rainfall Measuring Mission (TRMM) in November 1997 and the detailed coverage of the U.S. National Lightning Detection Network (NLDN), such interannual changes in lightning activity can be examined with far greater detail than ever before. For the 1997-98 ENSO event the most significant year-to-year changes in lightning frequency worldwide occurred along the Gulf Coast and within the Gulf of Mexico basin during the Northern Hemisphere winter. Within a broad swath across the northern Gulf of Mexico basin there is a 100-150% increase in lightning days year-to-year (a peak of 33 days in the winter of 1997-98 vs. only 15 days or fewer in both the 1996-97 and 1998-99 winter). In addition, there is a nearly 200% increase in lightning hours (a peak of 138 hours in 1996-97 vs. 50 hours in both 1996-97 and 1998-99). The increase in lightning activity during ENSO occurs in association with a 100% increase in the number of synoptic scale cyclones that developed within or moved through the Gulf basin. The primary variables controlling these enhancements in thunderstorm activity are the position and strength of the jet stream.

  13. Heat Pump Water Heater Ducting Strategies with Encapsulated Attics in Climate Zones 2 and 4

    Energy Technology Data Exchange (ETDEWEB)

    Sweet, M. L. [Southface Energy Inst., Upper Marlboro, MD (United States); Francisco, A.; Roberts, S. G.

    2016-05-01

    The focus of this study is on the performance of HPWHs with several different duct configurations and their effects on whole building heating, cooling, and moisture loads. A.O. Smith 60 gallon Voltex (PHPT-60) heat pump water heaters (HPWHs) were included at two project sites and ducted to or located within spray foamed encapsulated attics. The effect of ducting a HPWH's air stream does not diminish its efficiency if the ducting does not reduce intake air temperature, which expands HPWH application to confined areas. Exhaust ducts should be insulated to avoid condensation on the exterior, however this imposes a risk of condensation occurring in the duct's interior near the HPWH due to large variation of temperatures between the compressor and the duct and the presence of bulk moisture around the condenser. The HPWH's air conditioning impact on HVAC equipment loads is minimal when the intake and exhaust air streams are connected to a sealed attic and not the living space. A HPWH is not suitable as a replacement dehumidifier in sealed attics as peak moisture loads were observed to only be reduced if the heat pump operated during the morning. It appears that the intake air temperature and humidity was the most dominant variable affecting HPWH performance. Different ducting strategies such as exhaust duct only, intake duct only, and exhaust and intake ducting did not have any effect on HPWH performance.

  14. Survey of the fatty acid composition of retail milk in the United States including regional and seasonal variations.

    Science.gov (United States)

    O'Donnell-Megaro, A M; Barbano, D M; Bauman, D E

    2011-01-01

    Consumers are increasingly aware that food components have the potential to influence human health maintenance and disease prevention, and dietary fatty acids (FA) have been of special interest. It has been 25 years since the last survey of US milk FA composition, and during this interval substantial changes in dairy rations have occurred, including increased use of total mixed rations and byproduct feeds as well as the routine use of lipid and FA supplements. Furthermore, analytical procedures have improved allowing greater detail in the routine analysis of FA, especially trans FA. Our objective was to survey US milk fat and determine its FA composition. We obtained samples of fluid milk from 56 milk processing plants across the US every 3 mo for one year to capture seasonal and geographical variations. Processing plants were selected based on the criteria that they represented 50% or more of the fluid milk produced in that area. An overall summary of the milk fat analysis indicated that saturated fatty acids comprised 63.7% of total milk FA with palmitic and stearic acids representing the majority (44.1 and 18.3% of total saturated fatty acids, respectively). Unsaturated fatty acids were 33.2% of total milk FA with oleic acid predominating (71.0% of total unsaturated fatty acids). These values are comparable to those of the previous survey in 1984, considering differences in analytical techniques. Trans FA represented 3.2% of total FA, with vaccenic acid being the major trans isomer (46.5% of total trans FA). Cis-9, trans-11 18:2 conjugated linoleic acid represented 0.55% total milk FA, and the major n-3 FA (linolenic acid, 18:3) composed 0.38%. Analyses for seasonal and regional effects indicated statistical differences for some FA, but these were minor from an overall human nutrition perspective as the FA profile for all samples were numerically similar. Overall, the present study provides a valuable database for current FA composition of US fluid milk, and

  15. Effects of heater location and heater size on the natural convection heat transfer in a square cavity using finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, Ich Long; Byon, Chan [Yeungnam University, Gyeongsan (Korea, Republic of)

    2015-07-15

    Finite element method was used to investigate the effects of heater location and heater size on the natural convection heat transfer in a 2D square cavity heated partially or fully from below and cooled from above. Rayleigh number (5 X 10{sup 2} ≤ Ra ≤ 5X10{sup 5}), heater size (0.1 ≤ D/L ≤ 1.0), and heater location (0.1 ≤ x{sub h}/L ≤ 0.5) were considered. Numerical results indicated that the average Nusselt number (Nu{sub m}) increases as the heater size decreases. In addition, when x{sub h}/L is less than 0.4, Nu{sub m} increases as x{sub h}/L increases, and Num decreases again for a larger value of x{sub h}/L. However, this trend changes when Ra is less than 10{sup 4}, suggesting that Nu{sub m} attains its maximum value at the region close to the bottom surface center. This study aims to gain insight into the behaviors of natural convection in order to potentially improve internal natural convection heat transfer.

  16. Monitoring Groundwater Variations from Satellite Gravimetry and Hydrological Models: A Comparison with in-situ Measurements in the Mid-Atlantic Region of the United States

    Directory of Open Access Journals (Sweden)

    Ruya Xiao

    2015-01-01

    Full Text Available Aimed at mapping time variations in the Earth’s gravity field, the Gravity Recovery and Climate Experiment (GRACE satellite mission is applicable to access terrestrial water storage (TWS, which mainly includes groundwater, soil moisture (SM, and snow. In this study, SM and accumulated snow water equivalent (SWE are simulated by the Global Land Data Assimilation System (GLDAS land surface models (LSMs and then used to isolate groundwater anomalies from GRACE-derived TWS in Pennsylvania and New York States of the Mid-Atlantic region of the United States. The monitoring well water-level records from the U.S. Geological Survey Ground-Water Climate Response Network from January 2005 to December 2011 are used for validation. The groundwater results from different combinations of GRACE products (from three institutions, CSR, GFZ and JPL and GLDAS LSMs (CLM, NOAH and VIC are compared and evaluated with in-situ measurements. The intercomparison analysis shows that the solution obtained through removing averaged simulated SM and SWE of the three LSMs from the averaged GRACE-derived TWS of the three centers would be the most robust to reduce the noises, and increase the confidence consequently. Although discrepancy exists, the GRACE-GLDAS estimated groundwater variations generally agree with in-situ observations. For monthly scales, their correlation coefficient reaches 0.70 at 95% confidence level with the RMSE of the differences of 2.6 cm. Two-tailed Mann-Kendall trend test results show that there is no significant groundwater gain or loss in this region over the study period. The GRACE time-variable field solutions and GLDAS simulations provide precise and reliable data sets in illustrating the regional groundwater storage variations, and the application will be meaningful and invaluable when applied to the data-poor regions.

  17. 高压加热器运行中存在的问题及对策%Existing Problems and Countermeasure on the Operation of High Pressure Heater

    Institute of Scientific and Technical Information of China (English)

    李航; 魏科

    2012-01-01

    Pointed out that the thermal power plant of high pressure heater leakage of high pressure heater leakage phenomenon,after the influence on the unit,in response to high pressure heater tubes and expanding mouth leak exists,automatic feed water bypass sealing is poor,poor drainage system automatically into some of the more common problems,analyze the reasons of the causes,proposes treatment countermeasures.%指出了火力电厂高压加热器泄漏的现象,高压加热器泄漏后对机组的影响,针对高压加热器存在的管子及胀口泄漏、给水自动旁路密封不佳、疏水系统自动投入不良等一些较普遍的问题,分析问题的成因,提出针对性的处理对策。

  18. Experimental analysis of distinct design of a batch solar water heater with integrated collector storage system

    Directory of Open Access Journals (Sweden)

    Varghese Jaji

    2007-01-01

    Full Text Available The performance of a new design of batch solar water heater has been studied. In this system, the collector and storage were installed in one unit. Unlike the conventional design consisting of small diameter water tubes, it has a single large diameter drum which serves the dual purpose of absorber tube and storage tank. In principle it is a compound parabolic collector. The drum is sized to have a storage capacity of 100 liter to serve a family of four persons. The tests were carried out with a single glass cover and two glass covers. The tests were repeated for several days. Performance analysis of the collector has revealed that it has maximum mean daily efficiency with two glass covers as high as 37.2%. The maximum water temperature in the storage tank of 60°C has been achieved for a clear day operation at an average solar beam radiation level of 680 W/m2 and ambient temperature of 32°C. To judge the operating characteristics and to synchronize utility pattern of the collector, the different parameters such as efficiency, mean plate temperature and mass flow rate has been investigated.

  19. An economic and performance design study of solar preheaters for domestic hot water heaters in North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.B.; Smetana, F.O.

    1977-03-01

    The performance and estimated material costs for several solar preheaters for domestic hot water heaters using insolation levels present in North Carolina are presented. The effects of monthly variations in insolation and the direction of incident radiation are included. Demand is assumed at 13 gallons (49.2 liters) per day per person. The study shows that a closed circulation system with 82 gallons (310 liters) of preheated storage and 53.4 cu ft (4.94 cu m) of collector surface with single cover can be expected to cost about $800 and to repay it capital cost and interest (at 8%) in 5.2 years, assuming present electric rates increase at 5% per year.

  20. An economic and performance design study of solar preheaters for domestic hot water heaters in North Carolina

    Science.gov (United States)

    Jones, C. B.; Smetana, F. O.

    1977-01-01

    The performance and estimated material costs for several solar preheaters for domestic hot water heaters using isolation levels present in North Carolina are presented. The effects of monthly variations in isolation and the direction of incident radiation are included. Demand is assumed at 13 gallons (49.2 liters) per day per person. The study shows that a closed circulation system with 82 gallons (310 liters) of preheated storage and 53.4 cu ft (4.94 cu m) of collector surface with single cover can be expected to cost about $800 and to repay it capital cost and interest (at 8%) in 5.2 years, assuming present electric rates increase at 5% per year.

  1. Swift BAT Thermal Recovery After Loop Heat Pipe #0 Secondary Heater Controller Failure in October 2015

    Science.gov (United States)

    Choi, Michael K.

    2016-01-01

    The Swift BAT LHP #0 primary heater controller failed on March 31, 2010. It has been disabled. On October 31, 2015, the secondary heater controller of this LHP failed. On November 1, 2015, the LHP #0 CC temperature increased to as 18.6 C, despite that the secondary heater controller set point was 8.8 C. It caused the average DM XA1 temperature to increase to 25.9 C, which was 5 C warmer than nominal. As a result, the detectors became noisy. To solve this problem, the LHP #1 secondary heater controller set point was decreased in 0.5 C decrements to 2.2 C. The set-point decrease restored the average DM XA1 temperature to a nominal value of 19.7 C on November 21.

  2. Numerical Simulation of Induction Through-Heater in Dynamic Operation Mode

    Directory of Open Access Journals (Sweden)

    SCURTU Gheorghe Lucian

    2013-05-01

    Full Text Available The numeric model used in this paper is based on the finite element method and is aiming an inductive heating in volume of a cylindrical structure in a dynamic operation mode. Nowadays the inductionthrough-heaters are usually designed to provide the required characteristics in “quasi” steady-state operation mode mainly. However, in industrial practice the heaters can operate under various disturbances more than half of time, so the transient process playsignificant role in effectiveness and quality of the heating. Investigation of dynamic characteristics of the heaters in dynamic modes can be only done by numerical modeling based on special algorithms providing a time loop additionally to coupling betweenelectromagnetic and thermal analysis. Such numerical models have been developed and used for investigation of dynamic modes for heating billets. The results of numerical simulation can be used for design ofinduction through-heaters and improvement of their characteristics in dynamic operation modes.

  3. Analytical model for ring heater thermal compensation in the Advanced Laser Interferometer Gravitational-wave Observatory.

    Science.gov (United States)

    Ramette, Joshua; Kasprzack, Marie; Brooks, Aidan; Blair, Carl; Wang, Haoyu; Heintze, Matthew

    2016-04-01

    Advanced laser interferometer gravitational-wave detectors use high laser power to achieve design sensitivity. A small part of this power is absorbed in the interferometer cavity mirrors where it creates thermal lenses, causing aberrations in the main laser beam that must be minimized by the actuation of "ring heaters," which are additional heater elements that are aimed to reduce the temperature gradients in the mirrors. In this article we derive the first, to the best of our knowledge, analytical model of the temperature field generated by an ideal ring heater. We express the resulting optical aberration contribution to the main laser beam in this axisymmetric case. Used in conjunction with wavefront measurements, our model provides a more complete understanding of the thermal state of the cavity mirrors and will allow a more efficient use of the ring heaters in the Advanced Laser Interferometer Gravitational-wave Observatory.

  4. Self-regulating heater application to Shuttle/Centaur hydrazine fuel line thermal control

    Science.gov (United States)

    Unkrich, David B.

    1987-01-01

    The Shuttle/Centaur high energy upper stage vehicle thermal environments were more severe than previous Centaur vehicle thermal environments, creating need for a new hydrazine fuel line thermal control technique. Constant power heaters did not satisfy power dissipation requirements, because the power required to maintain fuel line thermal control during cold conditions exceeded the maximum power allowable during hot conditions. Therefore, a Raychem Thermolimit self-regulating heater was selected for this application, and was attached to the hydrazine fuel line with Kapton and aluminum foil tapes. Fuel line/heater thermal modeling and subsequent thermal vacuum chamber testing simulated heater thermal performance during all worst-case Shuttle/Centaur thermal environmental conditions. Fuel line temperatures were maintained between the 4C to 71C limits during all analytical and test cases. Finally, the thermal model predictions were correlated with the test data, thereby ensuring that the model would provide satisfactory predictions for future missions and/or vehicles.

  5. REFINED METHOD OF COMPUTING MODES OF OPERATING OF CAPACITY-TYPE SOLAR HEATERS OF

    Directory of Open Access Journals (Sweden)

    Ermuratschii Vl.V.

    2008-04-01

    Full Text Available The refined method procedure of thermal modes of solar heaters of water of the capacity type, based on use of an electro-thermal equivalent circuit and a method of central potentials is presented.

  6. Towards the Development of a Novel CNTs-based Flexible Mild Heater for Art Conservation

    Directory of Open Access Journals (Sweden)

    Tomas Markevicius

    2014-03-01

    tests performed on a series of prototypes of the designed heaters showed that the device was able to convey uniform heating on different working materials, thus proving to be effective for thermal consolidation.

  7. Temperature Profiles During Quenches in LHC Superconducting Dipole Magnets Protected by Quench Heaters

    CERN Document Server

    Maroussov, V; Siemko, A

    2000-01-01

    The efficiency of the magnet protection by quench heaters was studied using a novel method which derives the temperature profile in a superconducting magnet during a quench from measured voltage signals. In several Large Hadron Collider single aperture dipole models, temperature profiles and temperature gradients in the magnet coil have been evaluated in the case of protection by different sets of quench heaters and different powering and protection parameters. The influence of the insulation thickness between the quench heaters and the coil has also been considered. The results show clear correlation between the positions of quench heaters, magnet protection parameters and temperature profiles. This study allowed a better understanding of the quench process mechanisms and the efficiency assessment of the different protection schemes.

  8. Natural Convection of Nanofluids in a Square Enclosure with a Protruding Heater

    Directory of Open Access Journals (Sweden)

    J. Guiet

    2012-01-01

    Full Text Available This paper reports a numerical study on natural convection from a protruding heater located at the bottom of a square cavity filled with a copper-water nanofluid. The vertical walls of the cavity are cooled isothermally; the horizontal ones are adiabatic, and the heater is attached to the bottom wall. The heat source is assumed either to be isothermal or to have a constant heat flux. The effective viscosity and thermal conductivity of the nanofluid are modeled according to Brinkman and Patel, respectively. Numerical solutions of the full-governing equations, based on the lattice Boltzmann method, are obtained for a wide range of the governing parameters: the Rayleigh number, Ra; the Prandtl number, Pr; the geometrical parameters specifying the heater; the volume fraction of nanoparticles, Φ. For a particular geometry, it has been found that, for a given Ra, heat transfer is enhanced with increasing Φ, independently of the thermal boundary condition applied on the heater.

  9. Ultrathin Polyimide-Stainless Steel Heater for Vacuum System Bake-out

    CERN Document Server

    Rathjen, Christian; Henrist, Bernard; Kölemeijer, Wilhelmus; Libera, Bruno; Lutkiewicz, Przemyslaw

    2005-01-01

    Space constraints in several normal conducting magnets of the LHC required the development of a dedicated permanent heater for vacuum chamber bake-out. The new heater consists of stainless steel bands inside layers of polyimide. The overall heater thickness is about 0.3 mm. The low magnetic permeability is suitable for applications in magnetic fields. The material combination allows for temperatures high enough to activate a NEG coating. Fabrication is performed in consecutive steps of tape wrapping. Automation makes high volume production at low costs possible. About 800 m of warm vacuum system of the long straight sections of the LHC will be equipped with the new heater. This paper covers experience gained at CERN from studies up to industrialization.

  10. A Simple Substrate Heater Device With Temperature Controller for Thin Film Preparation

    Directory of Open Access Journals (Sweden)

    G. Rendón

    2012-08-01

    Full Text Available A simple substrate heater and its temperature controller were designed and built in order to prepare thin films in a highvacuum deposition system. The substrate heater was elaborated with a glass-ceramic body and a molybdenum foilheater. The applied power and the temperature are regulated by a power controller board using a microcontrollerprogrammed with a proportional-integrative-derivative algorithm. The heater/controller system was tested in a highvacuum deposition system and the results of its characterization at 100, 200, 300 and 400 °C are presented. Avariation in temperature better than ± 0.5 °C was obtained for all the tested temperatures. An application of thesubstrate heater is demonstrated by evaporating gold thin films on heated glass substrates.

  11. Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 3, Water heaters, pool heaters, direct heating equipment, and mobile home furnaces

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This is Volume 3 in a series of documents on energy efficiency of consumer products. This volume discusses energy efficiency of water heaters. Water heaters are defined by NAECA as products that utilize oil, gas, or electricity to heat potable water for use outside the heater upon demand. These are major appliances, which use a large portion (18% on average) of total energy consumed per household (1). They differ from most other appliances in that they are usually installed in obscure locations as part of the plumbing and are ignored until they fail. Residential water heaters are capable of heating water up to 180{degrees}F, although the setpoints are usually set lower.

  12. Energetic Performances Study of an Integrated Collector Storage Solar Water Heater

    Directory of Open Access Journals (Sweden)

    O. Helal

    2010-01-01

    Full Text Available Problem statement: Although that the interest attributed to the solar energy remains relatively limited, we attend today to the conception of several installations using the sun as energy source among which we quote the solar water heater. Approach: A study of energetic performances was taken on an integrated collector/storage solar water heater made in the National School of Engineers of Gabes. This water heater is equipped with a concentration system containing a reflector composed of three parabolic branches favorating a better absorption of solar radiance. Results: The comparison between this system and two other systems of solar water heater, composed of a storage ball with asymmetrical CPC and symmetrical CPC, showed important energetic performances despite the simplicity and the little cost of the collector. Conclusion: Several improvements are necessary to increase the direct flow whilst decrease the thermal losses and therefore make the system simpler to be installed on the building roof.

  13. Energy-efficient tunable silicon photonic micro-resonator with graphene transparent nano-heaters

    CERN Document Server

    Yu, Longhai; Dai, Daoxin; He, Sailing

    2015-01-01

    Thermally-tuning silicon micro-cavities are versatile and beneficial elements in low-cost large-scale photonic integrated circuits (PICs). Traditional metal heaters used for thermal tuning in silicon micro-cavities usually need a thick SiO2 upper-cladding layer, which will introduce some disadvantages including low response speed, low heating efficiency, low achievable temperature and complicated fabrication processes. In this paper, we propose and experimentally demonstrate thermally-tuning silicon micro-disk resonators by introducing graphene transparent nano-heaters, which contacts the silicon core directly without any isolator layer. This makes the graphene transparent nano-heater potentially to have excellent performances in terms of the heating efficiency, the temporal response and the achievable temperature. It is also shown that the graphene nano-heater is convenient to be used in ultrasmall photonic integrated devices due to the single-atom thickness and excellent flexibility of graphene. Both experi...

  14. Analysis of exergy and parametric study of a v-corrugated solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Hedayatizadeh, Mahdi [University of Tabriz, Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tabriz (Iran, Islamic Republic of); University of Birjand, Faculty of Agriculture, P.O. Box 97175/331, Birjand (Iran, Islamic Republic of); Ajabshirchi, Yahya [University of Tabriz, Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tabriz (Iran, Islamic Republic of); Sarhaddi, Faramarz; Farahat, Said [University of Sistan and Baluchestan, Department of Mechanical Engineering, Faculty of Engineering, P.O. Box 98164/161, Zahedan (Iran, Islamic Republic of); Safavinejad, Ali [University of Birjand, Department of Mechanical Engineering, Faculty of Engineering, Birjand (Iran, Islamic Republic of); Chaji, Hossein [University of Tabriz, Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tabriz (Iran, Islamic Republic of); Center of Agriculture and Natural Resources of Khorasan Razavi Province, Ministry of Agriculture, Mashhad (Iran, Islamic Republic of)

    2012-07-15

    Solar air heater requires investigation for enhancement of solar energy conversion into heat. Different configurations with various artificial roughness geometries are proposed to date. In present study attention is paid on ways leading to more delivery of exergy by a v-corrugated solar air heater through parametric study. Effects of aspect ratio of the collector, inlet air temperature, mass flow rate per collector area etc. are studied. (orig.)

  15. Economics of residential gas furnaces and water heaters in US new construction market

    OpenAIRE

    Lekov, Alex B.; Franco, Victor H.; Wong-Parodi, Gabrielle; McMahon, James E.; CHAN, Peter

    2010-01-01

    New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

  16. PREDICTION OF OPTIMUM ANGLE OF SOLAR WATER HEATER FOR COIMBATORE LOCATION

    OpenAIRE

    M. Sekar; DR M. SAKTHIVEL; O. MANIYARASU; N.ALAGU MURUGAN

    2013-01-01

    The objective of this work was to investigate ways to enhance the performance of solar water heater system to encourage many households using it. The integrated collector storage is the type of solar water heater that has retained its existence for well over a century. The flat absorber plate integrated collector storage type is a relatively recent addition. Being effective, low cost and simple to manufacture, their importance has been further enhanced by the recent upsurge in efforts to effe...

  17. PREDICTION OF OPTIMUM ANGLE OF SOLAR WATER HEATER FOR COIMBATORE LOCATION

    Directory of Open Access Journals (Sweden)

    M. SEKAR

    2013-04-01

    Full Text Available The objective of this work was to investigate ways to enhance the performance of solar water heater system to encourage many households using it. The integrated collector storage is the type of solar water heater that has retained its existence for well over a century. The flat absorber plate integrated collector storage type is a relatively recent addition. Being effective, low cost and simple to manufacture, their importance has been further enhanced by the recent upsurge in efforts to effectively tap renewable energy resources. Having different inclinations based on latitude, the design of flat plate heaters can benefit from extensive amount of research on the topic of natural convection in inclined cavities. The thermal performance of the heater is recorded experimentally at angles 0°–30° from horizontal, in 10° intervals. It was found that for any given constant value of heat flux, the performance of the heater is a strong function of the angle of inclination. The optimum configuration of the heater for Coimbatore location is also evaluated.

  18. Solair heater program: solair applications study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1977-12-01

    General Electric has designed and tested a low-cost solar system using a vacuum tube solar air heater under ERDA Contract E(11-1)-2705. This contract extension has been provided to evaluate various applications of this solar collector. The evaluation identified attractive applications, evaluated corresponding control procedures, estimated system performance, compared economically insolation and insulation, and evaluated the repackaging of off-the-shelf equipment for improved cost effectiveness. The results of this study prompted General Electric's marketing group to do a detailed commercialization study of a residential domestic water heating system using the Solair concept which has been selected as the most attractive application. Other attractive applications are space/domestic water heating and a heat pump assisted solar system/domestic water heating where the heat pump and the solar system function in parallel. A prime advantage of heated air solar systems over liquid systems is cost and longer life which results in higher BTU's/dollar. Other air system advantages are no liquid leakage problems, no toxicity of freezing problems, and less complicated equipment. A hybrid solar system has been identified that can improve the market penetration of solar energy. This system would use the existing mass of the house for energy storage thereby reducing solar cost and complexity. Adequate performance can be obtained with house temperature swings comparable to those used in nighttime setback of the thermostat. Details of this system are provided.

  19. Heater induced thermal effects on the LTP dynamics

    CERN Document Server

    Gibert, Ferran; Lobo, Alberto; Díaz-Aguiló, Marc; Mateos, Ignacio; Karnesis, Nikolaos; Sanjuán, Josep; Gesa, Lluís; lloro, Ivan; Martín, Víctor

    2013-01-01

    The STOC (Science and Technology Operations Centre) simulator of the LPF (LISA PathFinder) mission is intended to provide a validation tool for the mission operations tele-commanding chain, as well as for a deeper understanding of the underlying physical processes happening in the LTP (LISA Technology Package). Amongst the different physical effects that will appear onboard, temperature fluctuations in the Electrode Housing (EH) could generate disturbances on the interferometer (IFO) readouts, therefore they must be known and controlled. In this article we report on the latest progress in the analysis at IEEC of the LTP response to thermal signals injected by means of heaters. More specifically, we determine the transfer functions relating heat input signals to forces on the Test Masses (TMs) in the LTP frequency band, from 1 mHz to 30 mHz. A complete thermal model of the entire LPF spacecraft plus payload, elaborated and maintained at European Space Technology Center (ESTEC), was used to obtain temperature d...

  20. Solar-Powered Cooler and Heater for an Automobile Interior

    Science.gov (United States)

    Howard, Richard T.

    2006-01-01

    The apparatus would include a solar photovoltaic panel mounted on the roof and a panellike assembly mounted in a window opening. The window-mounted assembly would include a stack of thermoelectric devices sandwiched between two heat sinks. A fan would circulate interior air over one heat sink. Another fan would circulate exterior air over the other heat sink. The fans and the thermoelectric devices would be powered by the solar photovoltaic panel. By means of a double-pole, double-throw switch, the panel voltage fed to the thermoelectric stack would be set to the desired polarity: For cooling operation, the chosen polarity would be one in which the thermoelectric devices transport heat from the inside heat sink to the outside one; for heating operation, the opposite polarity would be chosen. Because thermoelectric devices are more efficient in heating than in cooling, this apparatus would be more effective as a heater than as a cooler. However, if the apparatus were to include means to circulate air between the outside and the inside without opening the windows, then its effectiveness as a cooler in a hot, sunny location would be increased.

  1. Solar Biogas Digester with Built-In Reverse Absorber Heater

    Directory of Open Access Journals (Sweden)

    Khasan S. Karimov

    2013-01-01

    Full Text Available In this work the design, fabrication and investigation of a solar biogas digester with built-in RAH (Reverse Absorber Heater is presented. The maximum temperature (50 o C inside of the methane tank was taken as a main parameter at the design of the digester. Using energy balance equation for the case of a static mass of fluid being heated; the parameters of thermal insulation of the methane tank were counted. The biogas digester is consisting of methane tank with built-in solar RAH to utilize solar energy for the heating of the slurry prepared from the different organic wastes (dung, sewage, food wastes etc. The methane tank was filled up to 70% of volume by organic wastes of the GIK Institute sewage, firstly, and secondly, by sewage and cow dung as well. During three months (October-December, 2009 and two months (February-March, 2010 the digester was investigated. The solar irradiance incident to the absorber, slurry's temperature and ambient temperature were measured. It was found that using sewage only and sewage with cow dung the retention times was 4 weeks and two weeks respectively and biogas quantity produced was 0.4 and 8.0 m 3 respectively. In addition, biogas upgradation scheme for removal of carbon dioxide, hydrogen sulphide and water vapor from biogas and conversion of biogas energy conversion into electric power is also discussed.

  2. Amikacin Dosing and Monitoring in Spinal Cord Injury Patients: Variation in Clinical Practice Between Spinal Injury Units and Differences in Experts' Recommendations

    Directory of Open Access Journals (Sweden)

    Subramanian Vaidyanathan

    2006-01-01

    Full Text Available The objective of this article was to determine the current practice on amikacin dosing and monitoring in spinal cord injury patients from spinal cord physicians and experts. Physicians from spinal units and clinical pharmacologists were asked to provide protocol for dosing and monitoring of amikacin therapy in spinal cord injury patients. In a spinal unit in Poland, amikacin is administered usually 0.5 g twice daily. A once-daily regimen of amikacin is never used and amikacin concentrations are not determined. In Belgium, Southport (U.K., Spain, and the VA McGuire Medical Center (Richmond, Virginia, amikacin is given once daily. Whereas peak and trough concentrations are determined in Belgium, only trough concentration is measured in Southport. In both these spinal units, modification of the dose is not routinely done with a nomogram. In Spain and the VA McGuire Medical Center, monitoring of serum amikacin concentration is not done unless a patient has renal impairment. In contrast, the dose/interval of amikacin is adjusted according to pharmacokinetic parameters at the Edward Hines VA Hospital (Hines, Illinois, where amikacin is administered q24h or q48h, depending on creatinine clearance. Spinal cord physicians from Denmark, Germany, and the Kessler Institute for Rehabilitation (West Orange, New Jersey state that they do not use amikacin in spinal injury patients. An expert from Canada does not recommend determining serum concentrations of amikacin, but emphasizes the value of monitoring ototoxicity and nephrotoxicity. Experts from New Zealand recommend amikacin in conventional twice- or thrice-daily dosing because of the theoretical increased risk of neuromuscular blockade and apnea with larger daily doses in spinal cord injury patients. On the contrary, experts from Greece, Israel, and the U.S. recommend once-daily dosing and determining amikacin pharmacokinetic parameters for each patient. As there is considerable variation in clinical

  3. Development of the HIFI band 3 and 4 mixer units

    NARCIS (Netherlands)

    De Lange, G.; Jackson, B.D.; Eggens, M.; Golstein, H.; Jochemsen, M.; Laauwen, W.M.; De Jong, L.; Kikken, S.; Kroug, M.; Zijlstra, T.

    2004-01-01

    We describe the current status of the HIFI mixer units for Band 3 and Band 4. The mixer units cover the 800-960 GHz and 960-1120 GHz frequency range and have a 4-8 GHz IF frequency band. The major requirements and the design strategy are described. Functional tests of the magnet, the de-flux heater,

  4. Factors associated with inter-institutional variations in sepsis rates of very-low-birth-weight infants in 34 Malaysian neonatal intensive care units.

    Science.gov (United States)

    Boo, Nem-Yun; Cheah, Irene Guat-Sim

    2016-03-01

    This study aimed to determine whether patient loads, infant status on admission and treatment interventions were significantly associated with inter-institutional variations in sepsis rates in very-low-birth-weight (VLBW) infants in the Malaysian National Neonatal Registry (MNNR). This was a retrospective study of 3,880 VLBW (≤ 1,500 g) infants admitted to 34 neonatal intensive care units (NICUs) in the MNNR. Sepsis was diagnosed in symptomatic infants with positive blood culture. Sepsis developed in 623 (16.1%) infants; 61 (9.8%) had early-onset sepsis (EOS) and 562 (90.2%) had late-onset sepsis (LOS). The median EOS rate of all NICUs was 1.0% (interquartile range [IQR] 0%, 2.0%). Compared with NICUs reporting no EOS (n = 14), NICUs reporting EOS (n = 20) had significantly higher patient loads (total live births, admissions, VLBW infants, outborns); more mothers with a history of abortions, and antenatal steroids and intrapartum antibiotic use; more infants requiring resuscitation procedures at birth; higher rates of surfactant therapy, pneumonia and insertion of central venous catheters. The median LOS rate of all NICUs was 14.5% (IQR 7.8%, 19.2%). Compared with NICUs with LOS rates below the first quartile (n = 8), those above the third quartile (n = 8) used less intrapartum antibiotics, and had significantly bigger and more mature infants, more outborns, as well as a higher number of sick infants requiring ventilator support and total parenteral nutrition. Patient loads, resuscitation at birth, status of infants on admission and treatment interventions were significantly associated with inter-institutional variations in sepsis. Copyright: © Singapore Medical Association.

  5. Salmonella enterica Infections in the United States and Assessment of Coefficients of Variation: A Novel Approach to Identify Epidemiologic Characteristics of Individual Serotypes, 1996-2011.

    Directory of Open Access Journals (Sweden)

    Amy L Boore

    Full Text Available Despite control efforts, salmonellosis continues to cause an estimated 1.2 million infections in the United States (US annually. We describe the incidence of salmonellosis in the US and introduce a novel approach to examine the epidemiologic similarities and differences of individual serotypes.Cases of salmonellosis in humans reported to the laboratory-based National Salmonella Surveillance System during 1996-2011 from US states were included. Coefficients of variation were used to describe distribution of incidence rates of common Salmonella serotypes by geographic region, age group and sex of patient, and month of sample isolation.During 1996-2011, more than 600,000 Salmonella isolates from humans were reported, with an average annual incidence of 13.1 cases/100,000 persons. The annual reported rate of Salmonella infections did not decrease during the study period. The top five most commonly reported serotypes, Typhimurium, Enteritidis, Newport, Heidelberg, and Javiana, accounted for 62% of fully serotyped isolates. Coefficients of variation showed the most geographically concentrated serotypes were often clustered in Gulf Coast states and were also more frequently found to be increasing in incidence. Serotypes clustered in particular months, age groups, and sex were also identified and described.Although overall incidence rates of Salmonella did not change over time, trends and epidemiological factors differed remarkably by serotype. A better understanding of Salmonella, facilitated by this comprehensive description of overall trends and unique characteristics of individual serotypes, will assist in responding to this disease and in planning and implementing prevention activities.

  6. HIV prevalence in severely malnourished children admitted to nutrition rehabilitation units in Malawi: Geographical & seasonal variations a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Maleta Kenneth

    2008-05-01

    Full Text Available Abstract Background Severe malnutrition in childhood associated with HIV infection presents a serious humanitarian and public health challenge in Southern Africa. The aim of this study was to collect country wide data on HIV infection patterns in severely malnourished children to guide the development of integrated care in a resource limited setting. Methods A cross sectional survey was conducted in 12 representative rural and urban Nutrition Rehabilitation Units (NRUs, from each of Malawi's 3 regions. All children and their caretakers admitted to each NRU over a two week period were offered HIV counselling and testing. Testing was carried out using two different rapid antibody tests, with PCR testing for discordant results. Children under 15 months were excluded, to avoid difficulties with interpretation of false positive rapid test results. The survey was conducted once in the dry/post-harvest season, and repeated in the rainy/hungry season. Results 570 children were eligible for study inclusion. Acceptability and uptake of HIV testing was high: 523(91.7% of carers consented for their children to take part; 368(70.6% themselves accepted testing. Overall HIV prevalence amongst children tested was 21.6%(95% confidence intervals, 18.2–25.5%. There was wide variation between individual NRUs: 2.0–50.0%. Geographical prevalence variations were significant between the three regions (p HIV prevalence was significantly higher in urban areas, 32.9%(95%CI 26.8–39.4% than in rural 13.2%(95%CI 9.5–17.6%(p NRU HIV prevalence rates were lower in the rainy/hungry season 18.4%(95%CI 14.7–22.7% than in the dry/post-harvest season 30.9%(95%CI 23.2–39.4% (p Conclusion There is a high prevalence of HIV infection in severely malnourished Malawian children attending NRUs with children in urban areas most likely to be infected. Testing for HIV is accepted by their carers in both urban and rural areas. NRUs could act as entry points to HIV treatment and

  7. Atmospheric mercury measurements at a suburban site in the Mid-Atlantic United States: Inter-annual, seasonal and diurnal variations and source-receptor relationships

    Science.gov (United States)

    Ren, Xinrong; Luke, Winston T.; Kelley, Paul; Cohen, Mark D.; Artz, Richard; Olson, Mark L.; Schmeltz, David; Puchalski, Melissa; Goldberg, Daniel L.; Ring, Allison; Mazzuca, Gina M.; Cummings, Kristin A.; Wojdan, Lisa; Preaux, Sandra; Stehr, Jeff W.

    2016-12-01

    Different atmospheric mercury forms have been measured at a suburban site in Beltsville, Maryland in the Mid-Atlantic United States since 2007 to investigate their inter-annual, seasonal and diurnal variabilities. Average concentrations and standard deviations of hourly measurements from 2007 to 2015 were 1.41 ± 0.23 ng m-3 for gaseous elemental mercury (GEM), 4.6 ± 33.7 pg m-3 for gaseous oxidized mercury (GOM), and 8.6 ± 56.8 pg m-3 for particulate-bound mercury (PBM). Observations show that on average, the rates of decrease were 0.020 ± 0.007 ng m-3 yr-1 (or 1.3 ± 0.5% yr-1, statistically significant, p-value 0.01) for PBM over this nine-year period. In addition, the collocated annual mercury wet deposition decreased at a rate of 0.51 ± 0.24 μg m-2 yr-2 (or 4.2 ± 1.9% yr-1, statistically insignificant, p-value > 0.01). Diurnal variation of GEM shows a slight peak in the morning, likely due to the shallow boundary layer. Seasonal variation of GEM shows lower levels in fall. Both diurnal variations of GOM and PBM show peaks in the afternoon likely due to the photochemical production of reactive mercury from the oxidation of GEM and the influence of boundary layer processes. Seasonally, GOM measurements show high levels in spring and constant low levels in the other three seasons, while PBM measurements exhibit higher levels from late fall to early spring and lower levels from late spring to fall. These measurement data were analyzed using the HYSPLIT back trajectory model in order to examine possible source-receptor relationships at this suburban site. Trajectory frequency analysis shows that high GEM/GOM/PBM events were generally associated with high frequencies of the trajectories passing through areas with high mercury emissions, while low GEM/GOM/PBM levels were largely associated the trajectories passing through relatively clean areas. This study indicates that local and regional sources appear to have a significant impact on the site and these

  8. Near Real-Time Assessment of Anatomic and Dosimetric Variations for Head and Neck Radiation Therapy via Graphics Processing Unit-based Dose Deformation Framework.

    Science.gov (United States)

    Qi, X Sharon; Santhanam, Anand; Neylon, John; Min, Yugang; Armstrong, Tess; Sheng, Ke; Staton, Robert J; Pukala, Jason; Pham, Andrew; Low, Daniel A; Lee, Steve P; Steinberg, Michael; Manon, Rafael; Chen, Allen M; Kupelian, Patrick

    2015-06-01

    The purpose of this study was to systematically monitor anatomic variations and their dosimetric consequences during intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer by using a graphics processing unit (GPU)-based deformable image registration (DIR) framework. Eleven IMRT H&N patients undergoing IMRT with daily megavoltage computed tomography (CT) and weekly kilovoltage CT (kVCT) scans were included in this analysis. Pretreatment kVCTs were automatically registered with their corresponding planning CTs through a GPU-based DIR framework. The deformation of each contoured structure in the H&N region was computed to account for nonrigid change in the patient setup. The Jacobian determinant of the planning target volumes and the surrounding critical structures were used to quantify anatomical volume changes. The actual delivered dose was calculated accounting for the organ deformation. The dose distribution uncertainties due to registration errors were estimated using a landmark-based gamma evaluation. Dramatic interfractional anatomic changes were observed. During the treatment course of 6 to 7 weeks, the parotid gland volumes changed up to 34.7%, and the center-of-mass displacement of the 2 parotid glands varied in the range of 0.9 to 8.8 mm. For the primary treatment volume, the cumulative minimum and mean and equivalent uniform doses assessed by the weekly kVCTs were lower than the planned doses by up to 14.9% (P=.14), 2% (P=.39), and 7.3% (P=.05), respectively. The cumulative mean doses were significantly higher than the planned dose for the left parotid (P=.03) and right parotid glands (P=.006). The computation including DIR and dose accumulation was ultrafast (∼45 seconds) with registration accuracy at the subvoxel level. A systematic analysis of anatomic variations in the H&N region and their dosimetric consequences is critical in improving treatment efficacy. Nearly real-time assessment of anatomic and dosimetric variations is

  9. Test Results From a Direct Drive Gas Reactor Simulator Coupled to a Brayton Power Conversion Unit

    Science.gov (United States)

    Hervol, David S.; Briggs, Maxwell H.; Owen, Albert K.; Bragg-Sitton, Shannon M.

    2009-01-01

    The Brayton Power Conversion Unit (BPCU) located at NASA Glenn Research Center (GRC) in Cleveland, OH is a closed cycle system incorporating a turboaltemator, recuperator, and gas cooler connected by gas ducts to an external gas heater. For this series of tests, the BPCU was modified by replacing the gas heater with the Direct Drive Gas heater or DOG. The DOG uses electric resistance heaters to simulate a fast spectrum nuclear reactor similar to those proposed for space power applications. The combined system thermal transient behavior was the focus of these tests. The BPCU was operated at various steady state points. At each point it was subjected to transient changes involving shaft rotational speed or DOG electrical input. This paper outlines the changes made to the test unit and describes the testing that took place along with the test results.

  10. Solar dryer with thermal storage and biomass-backup heater

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A. [Department of Physics and Biochemical Sciences, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Ngwalo, G. [Department of Mechanical Engineering, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi)

    2007-04-15

    An indirect type natural convection solar dryer with integrated collector-storage solar and biomass-backup heaters has been designed, constructed and evaluated. The major components of the dryer are biomass burner (with a rectangular duct and flue gas chimney), collector-storage thermal mass and drying chamber (with a conventional solar chimney). The thermal mass was placed in the top part of the biomass burner enclosure. The dryer was fabricated using simple materials, tools and skills, and it was tested in three modes of operation (solar, biomass and solar-biomass) by drying twelve batches of fresh pineapple (Ananas comosus), with each batch weighing about 20 kg. Meteorological conditions were monitored during the dehydration process. Moisture and vitamin C contents were determined in both fresh and dried samples. Results show that the thermal mass was capable of storing part of the absorbed solar energy and heat from the burner. It was possible to dry a batch of pineapples using solar energy only on clear days. Drying proceeded successfully even under unfavorable weather conditions in the solar-biomass mode of operation. In this operational mode, the dryer reduced the moisture content of pineapple slices from about 669 to 11% (db) and yielded a nutritious dried product. The average values of the final-day moisture-pickup efficiency were 15%, 11% and 13% in the solar, biomass and solar-biomass modes of operation respectively. It appears that the solar dryer is suitable for preservation of pineapples and other fresh foods. Further improvements to the system design are suggested. (author)

  11. Solvent-induced secondary building unit (SBU) variations in a series of Cu(II) metal-organic frameworks derived from a bifunctional ligand.

    Science.gov (United States)

    Chen, Di-Ming; Ma, Jian-Gong; Cheng, Peng

    2015-05-21

    The role of auxiliary solvents in the formation of metal-organic frameworks (MOFs) has been studied for a series of copper-based framework systems. Herein we show the formation of three different 3D ordered frameworks with the formulae {[Cu4(cpt)4Cl4]·2DMF·dioxane·3H2O}n (1), {[Cu8(cpt)4(Hcpt)2Cl7(μ3-OH)2(H2O)4]Cl3·4CH3CN}n (2), and {[Cu8(cpt)4Cl4(μ3-OH)2(μ4-O)2]Cl2·4H2O·2CH3CN·3MeOH}n (3) [Hcpt = 4-(4-carboxyphenyl)-1,2,4-triazole], respectively, from the same reaction mixture through varying auxiliary solvents of the medium. These MOFs were fully characterized by single-crystal X-ray diffraction, showing interesting secondary building unit (SBU) variations. The varied SBUs not only bring different framework architectures to these MOFs, but also affect their framework stability. Gas sorption studies of MOF 3 reveal high CO2-N2 selectivity at 298 K and 0.16 bar (a typical partial pressure of CO2 in an industrial flue gas). A high isosteric heat of adsorption (Qst) at zero loading (53 kJ mol(-1)) was also observed in MOF 3.

  12. Variation in Sexual Identification Among Behaviorally Bisexual Women in the Midwestern United States: Challenging the Established Methods for Collecting Data on Sexual Identity and Orientation.

    Science.gov (United States)

    Baldwin, Aleta; Schick, Vanessa R; Dodge, Brian; van Der Pol, Barbara; Herbenick, Debby; Sanders, Stephanie A; Fortenberry, J Dennis

    2016-08-03

    Collecting information on sexual identity is critical to ensuring the visibility of minority populations who face stigmatization and discrimination related to sexual identities. However, it is challenging to capture the nuances of sexual identity with traditional survey research methods. Using a mixed-methods approach, we gathered data on the sexual identities of 80 behaviorally bisexual women in the Midwestern United States through an online survey. When provided different types of measures (e.g., open ended and fixed response) and different contexts in which to identify (e.g., private and public), participants varied in how they reported their sexual identities. Qualitative analysis of participant narratives around identity change finds partitioning and ranking of attraction is a key component in understanding behaviorally bisexual women's identities. We further identify a division regarding the desired outcomes of identity development processes. Given the multiple ways in which participants identified depending upon the type of measure and the context specified, and the variation in identification over time, results support reconsidering the capability of typical measures and methods used in survey research to capture sexual identity information. Additionally, findings highlight the utility of including multiple, context-specific measures of sexual identities in future research.

  13. Socioeconomic Variation in the Effect of Economic Conditions on Marriage and Nonmarital Fertility in the United States: Evidence From the Great Recession.

    Science.gov (United States)

    Schneider, Daniel; Hastings, Orestes P

    2015-12-01

    The United States has become increasingly characterized by stark class divides in family structure. Poor women are less likely to marry than their more affluent counterparts but are far more likely to have a birth outside of marriage. Recent theoretical and qualitative work at the intersection of demography and cultural sociology suggests that these patterns are generated because poor women have high, nearly unattainable, economic standards for marriage but make a much weaker connection between economic standing and fertility decisions. We use the events of the Great Recession, leveraging variation in the severity of the crisis between years and across states, to examine how exposure to worse state-level economic conditions is related to poor women's likelihood of marriage and of having a nonmarital birth between 2008 and 2012. In accord with theory, we find that women of low socioeconomic status (SES) exposed to worse economic conditions are indeed somewhat less likely to marry. However, we also find that unmarried low-SES women exposed to worse economic conditions significantly reduce their fertility; economic standing is not disconnected from nonmarital fertility. Our results suggest that economic concerns were connected to fertility decisions for low-SES unmarried women during the Great Recession.

  14. Heat Pump Water Heater Technology: Experiences of Residential Consumers and Utilities

    Energy Technology Data Exchange (ETDEWEB)

    Ashdown, BG

    2004-08-04

    This paper presents a case study of the residential heat pump water heater (HPWH) market. Its principal purpose is to evaluate the extent to which the HPWH will penetrate the residential market sector, given current market trends, producer and consumer attributes, and technical parameters. The report's secondary purpose is to gather background information leading to a generic framework for conducting market analyses of technologies. This framework can be used to compare readiness and to factor attributes of market demand back into product design. This study is a rapid prototype analysis rather than a detailed case analysis. For this reason, primary data collection was limited and reliance on secondary sources was extensive. Despite having met its technical goals and having been on the market for twenty years, the HPWH has had virtually no impact on contributing to the nation's water heating. In some cases, HPWH reliability and quality control are well below market expectations, and early units developed a reputation for unreliability, especially when measured against conventional water heaters. In addition to reliability problems, first costs of HPWH units can be three to five times higher than conventional units. Without a solid, well-managed business plan, most consumers will not be drawn to this product. This is unfortunate. Despite its higher first costs, efficiency of an HPWH is double that of a conventional water heater. The HPWH also offers an attractive payback period of two to five years, depending on hot water usage. On a strict life-cycle basis it supplies hot water very cost effectively. Water heating accounts for 17% of the nation's residential consumption of electricity (see chart at left)--water heating is second only to space heating in total residential energy use. Simple arithmetic suggests that this figure could be reduced to the extent HPWH technology displaces conventional water heating. In addition, the HPWH offers other

  15. Emission factors of gaseous pollutants from recent kerosene space heaters and fuels available in France in 2010.

    Science.gov (United States)

    Carteret, M; Pauwels, J-F; Hanoune, B

    2012-08-01

    Laboratory measurements of the gaseous emission factors (EF) from two recent kerosene space heaters (wick and injector) with five different fuels have been conducted in an 8-m(3) environmental chamber. The two heaters tested were found to emit mainly CO(2), CO, NO, NO(2), and some volatile organic compounds (VOCs). NO(2) is continuously emitted during use, with an EF of 100-450 μg per g of consumed fuel. CO is normally emitted mainly during the first minutes of use (up to 3 mg/g). Formaldehyde and benzene EFs were quantified at 15 and 16 μg/g, respectively, for the wick heater. Some other VOCs, such as 1,3-butadiene, were detected with lower EFs. We demonstrated the unsuitability of a 'biofuel' containing fatty acid methyl esters for use with the wick heater, and that the accumulation of soot on the same heater, whatever the fuel, leads to a dramatic increase in the CO EF, up to 16 mg/g, which could be responsible for chronic and acute CO intoxications. Our results show that in spite of new technologies and emission standards for unvented kerosene space heaters, as well as for the fuels, the use of these heaters in indoor environments still leads to NO(x) levels in excess of current health recommendations. Whereas injection heaters generate more nitrogen oxides than wick heaters, prolonged use of the latter leads to a soot buildup, concomitant with high CO emissions, which could be responsible for acute and chronic intoxications. The use of a biofuel in a wick heater is also of concern. Maintenance of the heaters and adequate ventilation of the room during use of kerosene space heaters are therefore of prime importance to reduce personal exposure. © 2011 John Wiley & Sons A/S.

  16. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    T. Schirber, B. Schoenbauer

    2017-06-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high-performance water heaters difficult to justify economically. However, recent advancements in high-performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high-efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands.

  17. Effect of Uniformly and Nonuniformly Coated Al2O3 Nanoparticles over Glass Tube Heater on Pool Boiling

    Directory of Open Access Journals (Sweden)

    Nitin Doifode

    2016-01-01

    Full Text Available Effect of uniformly and nonuniformly coated Al2O3 nanoparticles over plain glass tube heater on pool boiling heat transfer was studied experimentally. A borosilicate glass tube coated with Al2O3 nanoparticle was used as test heater. The boiling behaviour was studied by using high speed camera. Result obtained for pool boiling shows enhancement in heat transfer for nanoparticle coated surface heater and compared with plain glass tube heater. Also heat transfer coefficient for nonuniformly coated nanoparticles was studied and compared with uniformly coated and plain glass tube. Coating effect of nanoparticles over glass tube increases its surface roughness and thereby creates more nucleation sites.

  18. Unit-specific calibration of Actigraph accelerometers in a mechanical setup - is it worth the effort? The effect on random output variation caused by technical inter-instrument variability in the laboratory and in the field

    DEFF Research Database (Denmark)

    Moeller, Niels C; Korsholm, Lars; Kristensen, Peter L

    2008-01-01

    during free living conditions. RESULTS: Calibration reduced inter-instrument variability considerably in the mechanical setup, both in the MTI instruments (raw SDbetween units = 195 counts*min-1 vs. calibrated SDbetween units = 65 counts*min-1) and in the CSA instruments (raw SDbetween units = 343 counts...... conditions had no apparent effect on inter-instrument variability. In all probability, the effect of technical calibration was primarily attenuated in the field by other more dominant sources of variation. However, routine technical assessments are still very important for determining the acceleration...

  19. Accelerator Magnet Quench Heater Technology and Quality Control Tests for the LHC High Luminosity Upgrade

    CERN Document Server

    Meuter, Florian

    The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) foresees the installation of new superconducting Nb3Sn magnets. For the protection of these magnets, quench heaters are placed on the magnet coils. The quench heater circuits are chemically etched from a stainless steel foil that is glued onto a flexible Polyimide film, using flexible printed circuit production technology. Approximately 500 quench heaters with a total length of about 3000 m are needed for the HL-LHC magnets. In order to keep the heater circuit electrical resistance in acceptable limits, an approximately 10 µm-thick Cu coating is applied onto the steel foil. The quality of this Cu coating has been found critical in the quench heater production. The work described in this thesis focuses on the characterisation of Cu coatings produced by electrolytic deposition, sputtering and electron beam evaporation. The quality of the Cu coatings from different manufacturers has been assessed for instance by ambient temperature electrical res...

  20. A modernized high-pressure heater protection system for nuclear and thermal power stations

    Science.gov (United States)

    Svyatkin, F. A.; Trifonov, N. N.; Ukhanova, M. G.; Tren'kin, V. B.; Koltunov, V. A.; Borovkov, A. I.; Klyavin, O. I.

    2013-09-01

    Experience gained from operation of high-pressure heaters and their protection systems serving to exclude ingress of water into the turbine is analyzed. A formula for determining the time for which the high-pressure heater shell steam space is filled when a rupture of tubes in it occurs is analyzed, and conclusions regarding the high-pressure heater design most advisable from this point of view are drawn. A typical structure of protection from increase of water level in the shell of high-pressure heaters used in domestically produced turbines for thermal and nuclear power stations is described, and examples illustrating this structure are given. Shortcomings of components used in the existing protection systems that may lead to an accident at the power station are considered. A modernized protection system intended to exclude the above-mentioned shortcomings was developed at the NPO Central Boiler-Turbine Institute and ZioMAR Engineering Company, and the design solutions used in this system are described. A mathematical model of the protection system's main elements (the admission and check valves) has been developed with participation of specialists from the St. Petersburg Polytechnic University, and a numerical investigation of these elements is carried out. The design version of surge tanks developed by specialists of the Central Boiler-Turbine Institute for excluding false operation of the high-pressure heater protection system is proposed.

  1. Development of the robot for pressurizer electric heater inspection and repairing

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Su, Yong Chil

    1998-01-01

    In this study a robot system has been developed for inspection and maintenance of the pressurizer and the rod heater. The developed robot system consists of four parts: two links, a support frame, a movable gripper, and a controller box. The robot is attached on the support frame, which is attached at the man-way flange of the pressurizer such that the robot is positioned inside pressurizer. To access arbitrary heater, at first two links horizontally rotate, and then the gripper suspended by two steel wires moves up and down by turing wire drum because the rod heaters are located about 8 meters under the robot and are arranged in two circular rows. The robot must be designed under several constraint such as its weight and collision with pressurizer wall or spray nozzle because the robot is positioned and moves inside the pressurizer. To verify that the designed robot is free from collision during installation procedure and it can access any desired rod heater, it is simulated by 3-dimensional graphic software (RobCAD). For evaluating stress of the support frame finite element analysis is performed by using the ANSYS code. For gripping the rod heater the passive self-locking mechanism is adopted, which is made up three balls and springs. Because the mechanism is very simple, it is very hardly defected than that adopted motor. (author). 11 refs., 8 tabs., 13 figs

  2. The effects of operating conditions on emissions from masonry heaters and sauna stoves

    Energy Technology Data Exchange (ETDEWEB)

    Tissari, Jarkko; Hytoenen, Kati; Sippula, Olli [Fine Particle and Aerosol Technology Laboratory, University of Kuopio, PO Box 1627, 70211 Kuopio (Finland); Jokiniemi, Jorma [Fine Particle and Aerosol Technology Laboratory, University of Kuopio, PO Box 1627, 70211 Kuopio (Finland)]|[VTT, Technical Research Centre of Finland, Fine Particles, PO Box 1000, 02044 VTT, Espoo (Finland)

    2009-03-15

    Emissions from masonry heaters and sauna stoves were studied. In the sauna stove the production of organic gaseous carbon (OGC) at 10 gC kg{sup -1} (per kilogram of fuel), carbon monoxide (CO) at 55 g kg{sup -1}, fine particle mass (PM{sub 1}) at 5 g kg{sup -1} and number emissions (N) at 1.8 x 10{sup 15} kg{sup -1} was higher than in other measured appliances. In a modern technology masonry heater with a unique grate, the emissions were very low: 0.4 gC kg{sup -1} OGC, 14 g kg{sup -1} CO and 0.7 g kg{sup -1} PM{sub 1}. Conventional masonry heaters, using small logs, clearly produced higher emissions when compared to using large logs. Doubling the fuel load caused emission factors to increase by up to 4- times (OGC), except for the number emission, which decreased from 4.0 x 10{sup 14} to 2.0 x 10{sup 14} kg{sup -1}. From the conventional masonry heater 90% of the PM was emitted during the firing phase. Its combustion process is different to that in stoves or conventional open fireplaces. The insufficient supply of air, due to too fast pyrolysis, and increased ash release, due to the high combustion temperature, are the main parameters which cause high particle and gas emissions in masonry heaters and sauna stoves. (author)

  3. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    Science.gov (United States)

    Krause, David L.; Kantzos, Pete T.

    2006-01-01

    For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110 W Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

  4. Experimental investigation of three different solar air heaters: Energy and exergy analyses

    Energy Technology Data Exchange (ETDEWEB)

    Alta, Deniz; Ertekin, C.; Yaldiz, Osman [Department of Farm Machinery, Faculty of Agricultural Engineering, Akdeniz University, 07059 Antalya (Turkey); Bilgili, Emin [Cukurova Agricultural Research Institute, Adana (Turkey)

    2010-10-15

    The present study aims to compare three different types of designed flat-plate solar air heaters, two having fins (Type II and Type III) and the other without fins (Type I), one of the heater with a fin had single glass cover (Type III) and the others had double glass covers (Type I and Type II). The energy and exergy output rates of the solar air heaters were evaluated for various air flow rates (25, 50 and 100 m{sup 3}/m{sup 2} h), tilt angle (0 , 15 and 30 ) and temperature conditions versus time. Based on the energy and exergy output rates, heater with double glass covers and fins (Type II) is more effective and the difference between the input and output air temperature is higher than of the others. Besides, it is found that the circulation time of air inside the heater played a role more important than of the number of transparent sheet. Lower air flow rates should be preferred in the applications of which temperature differences is more important. (author)

  5. Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    2017-03-08

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16-month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  6. Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, E. Weitzel

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16-month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  7. Modeling high resolution space-time variations in energy demand/CO2 emissions of human inhabited landscapes in the United States under a changing climate

    Science.gov (United States)

    Godbole, A. V.; Gurney, K. R.

    2010-12-01

    components of the human-climate system must be coupled in climate modeling efforts to better understand the impacts and feedbacks. To implement modeling strategies for coupling the human and climate systems, their interactions must first be examined in greater detail at high spatial and temporal resolutions. This work attempts to quantify the impact of high resolution variations in projected climate change on energy use/emissions in the United States. We develop a predictive model for the space heating component of residential and commercial energy demand by leveraging results from the high resolution fossil fuel CO2 inventory of the Vulcan Project (Gurney et al., 2009). This predictive model is driven by high resolution temperature data from the RegCM3 model obtained by implementing a downscaling algorithm (Chow and Levermore, 2007). We will present the energy use/emissions in both the space and time domain from two different predictive models highlighting strengths and weaknesses in both. Furthermore, we will explore high frequency variations in the projected temperature field and how these might place potentially large burdens on energy supply and delivery.

  8. Mercury in fishes from 21 national parks in the Western United States: inter- and intra-park variation in concentrations and ecological risk

    Science.gov (United States)

    Eagles-Smith, Collin A.; Willacker, James J.; Flanagan Pritz, Colleen M.

    2014-01-01

    Mercury (Hg) is a global contaminant and human activities have increased atmospheric Hg concentrations 3- to 5-fold during the past 150 years. This increased release into the atmosphere has resulted in elevated loadings to aquatic habitats where biogeochemical processes promote the microbial conversion of inorganic Hg to methylmercury, the bioavailable form of Hg. The physicochemical properties of Hg and its complex environmental cycle have resulted in some of the most remote and protected areas of the world becoming contaminated with Hg concentrations that threaten ecosystem and human health. The national park network in the United States is comprised of some of the most pristine and sensitive wilderness in North America. There is concern that via global distribution, Hg contamination could threaten the ecological integrity of aquatic communities in the parks and the wildlife that depends on them. In this study, we examined Hg concentrations in non-migratory freshwater fish in 86 sites across 21 national parks in the Western United States. We report Hg concentrations of more than 1,400 fish collected in waters extending over a 4,000 kilometer distance, from Alaska to the arid Southwest. Across all parks, sites, and species, fish total Hg (THg) concentrations ranged from 9.9 to 1,109 nanograms per gram wet weight (ng/g ww) with a mean of 77.7 ng/g ww. We found substantial variation in fish THg concentrations among and within parks, suggesting that patterns of Hg risk are driven by processes occurring at a combination of scales. Additionally, variation (up to 20-fold) in site-specific fish THg concentrations within individual parks suggests that more intensive sampling in some parks will be required to effectively characterize Hg contamination in western national parks. Across all fish sampled, only 5 percent had THg concentrations exceeding a benchmark (200 ng/g ww) associated with toxic responses within the fish themselves. However, Hg concentrations in 35 percent

  9. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-12

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  10. Light weight radioisotope heater unit (LWRHU) production for the Cassini mission

    Science.gov (United States)

    Rinehart, Gary H.

    1997-01-01

    The LWRHU is a 238PuO2 fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. The heat sources are required to maintain the temperature of specific components within normal operating ranges. The heat source consists of a hot-pressed 238PuO2 fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos National Laboratory has fabricated 180 heat sources, 157 of which will be used on the Cassini mission.

  11. Assessment of Performance Characteristic of Solar Air Heater with Assorted Geometries - A Review

    Directory of Open Access Journals (Sweden)

    Alok Kumar Rohit

    2016-01-01

    Full Text Available Artificial roughness is an efficient way for increasing the heat transfer rate in solar air heater with the corresponding improvement in its thermal performance. A viscous sub-layer is responsible for the low heat transfer coefficient between absorber plate and flowing air. Repeated ribs in form of artificial roughness are an effective way to increase the heat transfer rate and improving the performance of solar air heater. Artificial roughness of the absorber plate is much economical and effective way to improve the thermal performance of solar air heater. Several investigators have done various investigations to improve heat transfer coefficient with little penalty of friction factor. They have also developed different correlation for heat transfer coefficient and friction factor. The correlations developed for heat transfer and friction factor by various investigators have been reviewed and presented.

  12. STUDY ON THE OPTIMIZATION OF IGBT THERMAL MANAGEMENT FOR PTC HEATER

    Directory of Open Access Journals (Sweden)

    J. W. JEONG

    2015-12-01

    Full Text Available It is essential to optimize HVAC (Heating, Ventilation and Air-Conditioning system for a thermal plant or an electric vehicle since it has a significant effect on the thermal efficiency. PTC (positive temperature coefficient heaters are often used for a heating system and the power module of the PTC heaters, IGBT (insulated gate bipolar mode transistor, requires thermal management. In this study, in order to maximize the cooling performance for IGBT, a novel method that uses forced convection inside the HVAC duct with heat sinks was developed. In addition, heat sinks were optimized in terms of IGBT junction temperature and heat sink weight by 3-dimensional CFD (Computational Fluid Dynamics simulation. The results show that the junction temperature of IGBT for 5.6kW PTC heater can be maintained at about 335K.

  13. A novel domestic electric water heater model for a multi-objective demand side management program

    Energy Technology Data Exchange (ETDEWEB)

    Paull, Liam; Li, Howard; Chang, Liuchen [University of New Brunswick, Department of Electrical Engineering, Fredericton, NB (Canada)

    2010-12-15

    This paper presents a novel domestic hot water heater model to be used in a multi-objective demand side management program. The model incorporates both the thermal losses and the water usage to determine the temperature of the water in the tank. Water heater loads are extracted from household load data and then used to determine the household water usage patterns. The benefits of the model are: (1) the on/off state of the water heater and temperature of the water in the tank can be accurately predicted, and (2) it enables the development of water usage profiles so that users can be classified based on usage behaviour. As a result, the amount of ancillary services and peak shaving that can be achieved are accurately predictable and can be maximized without adversely affecting users. (author)

  14. Development of Industrially Produced Composite Quench Heaters for the LHC Superconducting Lattice Magnets

    CERN Document Server

    Szeless, Balázs; Calvone, F

    1996-01-01

    The quench heaters are vital elements for the protection of the LHC superconducting lattice magnets in the case of resistive transitions of the conductor. The basic concept of magnet protection and technical solutions are briefly presented. The quench heater consists of partially copper clad stainless steel strips sandwiched in between electric insulating carrier foils with electrical and mechanical properties such as to withstand high voltages, low temperatures, pressures and ionizing radiation. Testing of some commercial available electric insulation foils, polyimide (PI), polyetheretherketon (PEEK) and polyarylate (PA) and combinations of adhesive systems which are suitable for industrial processing are described. Possible industrial methods for series production for some 80 km of these composite quench heaters are indicated.

  15. Preliminary Modeling, Testing, and Analysis of a Gas Tankless Water Heater: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Hoeschele, M.; Springer, D.; Rudd, A.

    2008-05-01

    Today's gas tankless water heaters offer significant energy savings over conventional gas storage tank water heaters, but savings depends on the draw pattern. A one-node model incorporating heat exchanger mass is used to address this and other issues. Key model parameters are determined from least-squares regression on short-term data, including burner efficiency, thermal capacitance, and thermal loss coefficient. The calibrated model agrees with data to ~5% on Qgas, with temperature RMS deviation of ~4..deg..C. Efficiency with a standard realistic draw is 71%, compared to 81% predicted from standard energy-factors. Adding a small tank controlled by the tankless heater solves issues of oscillations with solar pre-heat, low-flow and hot-water-delay issues. Future work includes model refinements and developing optimal data protocols for model parameter extraction.

  16. An Experimental and Analytical Investigation of Stirling Space Power Converter Heater Head

    Science.gov (United States)

    Abdul-Aziz, Ali; Bartolotta, Paul; Tong, Mike; Allen, Gorden

    1995-01-01

    NASA has identified the Stirling power converter as a prime candidate for the next generation power system for space applications requiring 60000 hr of operation. To meet this long-term goal, several critical components of the power converter have been analyzed using advanced structural assessment methods. Perhaps the most critical component, because of its geometric complexity and operating environment, is the power converter's heater head. This report describes the life assessment of the heater head which includes the characterization of a viscoplastic material model, the thermal and structural analyses of the heater head, and the interpolation of fatigue and creep test results of a nickel-base superalloy, Udimet 720 LI (Low Inclusions), at several elevated temperatures for life prediction purposes.

  17. Study on Ag mesh/conductive oxide hybrid transparent electrode for film heaters

    Science.gov (United States)

    Kwon, Namyong; Kim, Kyohyeok; Heo, Jinhee; Yi, Insook; Chung, Ilsub

    2014-07-01

    Ag mesh-indium tin oxide (ITO) hybrid transparent conductive films were fabricated and evaluated for use in film heaters. PS monolayer templates were prepared using highly mono-dispersed PS spheres (11.2 μm) obtained by a filtering process with micro-sieves. At first, three Ag meshes with different sheet resistances (20, 100, and 300 Ω sq-1) and transmittances (70, 73, and 76%) were evaluated for film heaters in terms of voltage and long-term stability. Subsequently, in an effort to obtain better transmittance, Ag mesh-ITO hybrid heaters were fabricated utilizing finite ITO depositions. At the optimised ITO thickness (15 nm), the sheet resistance and the transmittance were 300 Ω sq-1 and 88%, respectively, which indicates that this material is a good potential candidate for an efficient defroster in vehicles.

  18. Performance estimation of artificially roughened solar air heater duct provided with continuous ribs

    Directory of Open Access Journals (Sweden)

    Mridul Sharma, Varun

    2010-09-01

    Full Text Available The use of an artificial roughness on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of a solar air heater. This paper presents a comparison of exergetic performance of solar air heaters having different types of geometry of roughness elements (continuous ribs on the absorber plate. The exergy efficiency has been computed by using the correlations for heat transfer and friction factor developed by various investigators within the investigated range of operating and system parameters. The exergy efficiency based criterion shows the better results at lower value of Re. There is not a single roughness geometry which gives best exergetic performance for whole range of Reynolds number. Solar air heater having rib-grooved and arc shaped wire as artificial roughness is found to have better exergy efficiency in the lower range of Reynolds number. However, smooth duct is found suitable in the higher range of Reynolds number.

  19. The benefit of solid oxide fuel cells with integrated air pre-heater

    Energy Technology Data Exchange (ETDEWEB)

    Costamagna, P. [Univ. degli Studi di Genova, Fac. di Ingegneria, ISTIC, Inst. di Ingegneria Chimica e di Processo `G.B. Bonino`, Genova (Italy)

    1997-11-01

    A new design has recently been proposed in the field of solid oxide fuel cells, consisting of a traditional electrochemical cell integrated with a pre-heater. In this paper a simulation model for the rectangular planar solid oxide fuel cell with integrated air pre-heater is presented. A two-dimensional stack simulation is presented as well, one axis coincides with the fuel flow direction, the other with the stack height. Local quantities such as current density, gas and solid temperatures are reported and cell characteristics predicted. In a parameter study, effects of oxygen utilisation and heat-transfer conditions in the pre-heater on the local temperature distribution of the solid structure are considered. As a result, the benefit of the new cell design becomes evident when low air flow rates are applied. A further advantage associated with the reduced flow rate is the low air temperature at the inlet. (orig.)

  20. Active compensation of wavefront aberrations by controllable heating of lens with electric film heater matrix.

    Science.gov (United States)

    Chen, Hua; Hou, Lv; Zhou, Xinglin

    2016-08-20

    We present a new apparatus for active compensation of wavefront aberrations by controllable heating of a lens using a film heater matrix. The annular electric film heater matrix, comprising 24 individual heaters, is attached to the periphery of a lens. Utilizing the linear superposition, and wavefront change proportional to the heating energy properties induced by heating, a controllable wavefront can be defined by solving a linear function. The two properties of wavefront change of a lens have been confirmed through a specially designed experiment. The feasibility of the compensation method is validated by compensating the wavefront of a plate lens. The results show that the wavefront of the lens changes from 12.52 to 2.95 nm rms after compensation. With a more precise electric controlling board, better results could be achieved.

  1. Effective efficiency prediction for discrete type of ribs used in solar air heaters

    Directory of Open Access Journals (Sweden)

    Muneesh Sethi, Mridul Sharma, Varun

    2010-03-01

    Full Text Available The use of an artificial roughness on a surface is an effective technique to enhance the heat transfer from the collector plate to the air in a solar air heater duct. However, artificial roughness leads to even more fluid pressure thereby increasing the pumping power. Number of geometries of roughness elements has been investigated on the heat transfer and friction characteristics of solar air heater ducts. This paper presents a comparison of effective efficiency of solar air heaters having different types of geometry of roughness elements (discrete ribs on the absorber plate. The effective efficiency has been computed by using the correlations for heat transfer and friction factor developed by various investigators within the investigated range of operating and system parameters.

  2. MATHEMATICAL AND INFORMATION SUPPORT FOR CALCULATION AND DESIGN OF TUBE GAS HEATERS LOCATED IN STRUCTURES

    Directory of Open Access Journals (Sweden)

    CHORNOMORETS H. Y.

    2016-02-01

    Full Text Available Raising of problem. For the design and construction of tube gas heaters in building structures to need solve the problems of analysis and synthesis of such heating system. The mathematical model of this system is consists of: mathematical model of the tube gas heater, mathematical model of heat distribution in the building structure and corresponding boundary conditions. To solve the tasks of analysis and synthesis must be appropriate mathematical and information support. Purpose. The purpose of this paper is to describe the developed mathematical and information support that solve the problems of analysis and synthesis of heating systems with gas tube heaters, located in building constructions.Conclusion. Mathematical support includes the development of algorithms and software for the numerical solution of problems analysis and synthesis heating system. Information support includes all the necessary parameters characterizing the thermal properties of materials which used in the heating system, and the parameters characterizing the heat exchange between the coolant and components of the heating system. It was developed algorithms for solving problems of analysis and synthesis heating system with tube gas heater located in structures to use evolutionary search algorithm and software. It was made experimental study and was obtained results allow to calculate the heat transfer from the gas-air mixture to the boundary surface of the building structure. This results and computation will provide full information support for solving problems of analysis and synthesis of the heating system. Was developed mathematical and software support, which allows to solve the problems of analysis and synthesis heating systems with gas tube heaters, located in building structures. Tube gas heaters located in the building structures allows with small capital expenditures to provide space heating. Is necessary to solve the problems of analysis (calculation and

  3. Water loss from the skin of term and preterm infants nursed under a radiant heater.

    Science.gov (United States)

    Kjartansson, S; Arsan, S; Hammarlund, K; Sjörs, G; Sedin, G

    1995-02-01

    The rate of evaporation from the skin (g/m2/h) was measured in 12 full-term and 16 preterm infants (gestational age 25-34 wk) both during incubator care and when nursed under a radiant heater. The method for evaporation rate measurement is noninvasive and based on determination of the water vapor pressure gradient close to the skin surface. Measurements were first made with the infant nursed in an incubator with a controlled environment with respect to humidity, temperature, and air velocity. The measurements in the term infants were performed at an ambient relative humidity (RH) of 50%, and in the preterm infants first at 50% and subsequently at 30-40%. Evaporation rate was then measured with the infant nursed under a radiant heater. In term infants, mean evaporation rate was 3.3 g/m2/h during incubator care (RH 50%) and 4.4 g/m2/h during care under the radiant heater. In preterm infants, the corresponding values were 15.5 g/m2/h in the incubator at RH 50%, 16.7 g/m2/h at RH 30-40%, and 17.9 g/m2/h under the radiant heater. It is concluded that the evaporative water loss from the skin depends on the ambient water vapor pressure, irrespective of whether the infant is nursed in an incubator or under a radiant heater. The higher rate of evaporation during care under a radiant heater is due to the lower ambient water vapor pressure and not to any direct effect of the nonionizing radiation on the skin.

  4. Optimized wood/pellet heater with flue gas condensation; Optimerad ved/pelletspanna med roekgaskondensering

    Energy Technology Data Exchange (ETDEWEB)

    Fredriksson, Christian; Ramstroem, Erik; Berge, Niklas [TPS Termiska Processer AB, Nykoeping (Sweden)

    2002-09-01

    To increase the efficiency of small-scale combustion equipment it is possible to cool the flue gas and condense the water vapor in the flue gas in a flue gas condenser. This also makes it possible to reduce the emissions of particles and unburnt hydrocarbon if the condenser is designed in a suitable way. This work concerns flue gas condensation with respect to the design of the condenser, the handling of the condensate and the integration of the flue gas condenser in a heating system from a technical and an economical point of view. The results from laboratory experiments shows that a flue gas condenser, designed as a plate heat exchanger, connected to a wood pellet fired heater reduces the emissions of both particles and unburnt hydrocarbons. A reduction of 10 to 77% of the particle content in the gas was achieved, the content of hydrocarbons (BTX) was reduced by 50 to 91 %. It was not possible to see any effect on the emissions by changing the design of the condenser, due to the relatively large scatter in the determined particle content in the gas. When it comes to cooling capacity the trends were however more clear; the cooling capacity was strongly dependent on the design of the condenser. It was possible to increase the cooling capacity of the condenser with 124% by changing the condenser design from a reference case with conventional design of the condenser with flat walls, to a design with a corrugated shape of the wall. For a typical domestic wood stove heater of 30 kW this means that the cooling capacity in a condenser under similar conditions increases from 3.3 to 7.4 kW. The addition of water in a spray in the gas upstream of the condenser had only a limited effect on the cooling capacity. The condensate from the condenser was analyzed with respect to the components that currently are regulated for disposal to the district sewer system. The analyses showed that the condensate most likely could be disposed to the sewer system directly without any

  5. Rate of heat transfer in polypropylene tubes in solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, J.; Mahmoodi, M. [Sharif University of Technology, Tehran (Iran). Chemical Engineering Dept.; Riazi, M.R. [Kuwait Univ., Safat (Kuwait). Chemical Engineering Dept.

    2003-06-01

    A heat transfer rate was determined for polypropylene tubes in solar water heaters for the Reynolds number range 800-5600. Experiments were conducted in ambient temperatures of 34 to 37 {sup o}C. Data were correlated in the form of Nusselt numbers as: Nu=0.0015 Re{sup 0.75}Pr{sup 1/3} with correlation coefficient of 0.95. Such data can be used to predict heat transfer rates in a polypropylene solar heater in Tehran where the experiments were performed. An application of the results is shown in an example. (author)

  6. Experimental comparison of alternative convection suppression arrangements for concentrating integral collector storage solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, M.; McGarrigle, P.; Eames, P.C. [Ulster Univ., School of the Built Environment, Newtownabbey, Northern Ireland (United Kingdom); Norton, B. [Dublin Inst. of Technology, Dublin (Ireland)

    2005-02-01

    An experimental investigation of an inverted absorber integrated collector storage solar water heater mounted in the tertiary cavity of a compound parabolic concentrator with a secondary cylindrical reflector has been performed under simulated solar conditions. The solar water heaters performance was determined with the aperture parallel to the simulator for a range of transparent baffles positioned at different locations within the collector cavity. Results indicate that glass baffles located at the upper portion of the exit aperture of the CPC can reduce thermal losses through convection suppression without significantly increasing optical losses. (Author)

  7. Boiling Heat Transfer Measurements on Highly Conductive Surfaces Using Microscale Heater and Temperature Arrays

    Science.gov (United States)

    Kim, J.; Bae, S. W.; Whitten, M. W.; Mullen, J. D.; Quine, R. W.; Kalkur, T. S.

    1999-01-01

    Two systems have been developed to study boiling heat transfer on the microscale. The first system utilizes a 32 x 32 array of diodes to measure the local temperature fluctuations during boiling on a silicon wafer heated from below. The second system utilizes an array of 96 microscale heaters each maintained at constant surface temperature using electronic feedback loops. The power required to keep each heater at constant temperature is measured, enabling the local heat transfer coefficient to be determined. Both of these systems as well as some preliminary results are discussed.

  8. Enhanced Heat Transfer Tubes for Absorber of Absorption Chiller/Heater

    Science.gov (United States)

    Furukawa, Masahiro; Sasaki, Naoe; Kaneko, Toshiyuki; Nosetani, Tadashi

    For the purpose of development of high performance absorption chiller/heater utilizing lithium bromide aqueous solution as working fluid, it is the most effective to improve the performance of absorber with the largest heat transfer area of the four heat exchangers. This paper introduces two kinds of double fluted tubes for the absorber of absorption chiller/heater. Arm tube and floral tube have about 40% higter heat transfer performance than the plain tube conventionally used in absorber. The former is manufactured by double drawbench process, while the latter by single drawbench process. Therefore, floral tube is expected to realize both high heat transfer perfoemance and low cost.

  9. Particle impaction efficiency and size distribution in a MSWI super heater tube bundle

    CERN Document Server

    Haugen, Nils Erland L; Bugge, Mette; Warnecke, Ragnar; Weghaus, Martin

    2010-01-01

    Particle impaction in the super heater geometry found in the municipal solid waste incinerator (MSWI) of GKS in Schweinfurt, Germany, has been investigated. By using direct numerical simulations for the fluid flow, inertial particles coupled to the fluid through the classical Stokes' drag law have been tracked. Focus has been on the effect of flow velocity, and it is shown that decreasing the flow velocity will drastically decrease the impaction efficiency for some particle radii. Finally particle size distribution measurements are presented and used to find quantitative mass fluxes both on the front and the back side of the tubes in the super heater tube bundle.

  10. Feed-water heaters alternative design comparison; Comparacion de disenos alternativos de calentadores

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    A procedure is presented for the alternative design comparison of feed water heaters, based in the failure records of damaged tubes during operation. The procedure is used for cases in which non-continuous or random inspections are made to the feed-water heaters. [Espanol] Se presenta un procedimiento para comparar disenos alternativos de calentadores, basandose en los registros de fallas de los tubos rotos acumuladas durante su operacion. El procedimiento se emplea para casos en los que se realizan inspecciones a los calentadores no continuas, ya sea periodicas o al azar.

  11. Experimental studies on PCM filled Flat Plate Solar Water Heater without and with Fresnel lens glazing

    Directory of Open Access Journals (Sweden)

    R. Sivakumar

    2016-07-01

    Full Text Available Flat Plate Solar Water Heater (FPSWH is commonly used to harvest solar energy. Solar concentration techniques help to achieve higher temperatures of energy. The aim of this article is to compare the performance of a Fresnel lens glazed Flat Plate Solar Water Heater with Phase Change Material (PCM with that provided with an ordinary glazing. The effect of solar concentration using Fresnel lens on energy storage in PCM and heat gained by water are studied and compared with that having an ordinary glazing. Experiments showed 47% improvements in the heat gained by water.

  12. 41 CFR 102-74.190 - Are portable heaters, fans and other such devices allowed in Government-controlled facilities?

    Science.gov (United States)

    2010-07-01

    ... § 102-74.190 Are portable heaters, fans and other such devices allowed in Government-controlled facilities? Federal agencies are prohibited from operating portable heaters, fans, and other such devices in... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Are portable...

  13. 10 CFR Appendix P to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Pool Heaters

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption... Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Pool Heaters 1. Test... 2.9 of ANSI Z21.56-1994. The measurement of energy consumption for oil-fired pool heaters in Btu is...

  14. Unit cell determination of coexisting post-perovskite and H-phase in (Mg,Fe)SiO3 using multigrain XRD: compositional variation across a laser heating spot at 119 GPa

    Science.gov (United States)

    Zhang, Li; Meng, Yue; Mao, Ho-kwang

    2016-12-01

    Multigrain X-ray diffraction (XRD) can be used to accurately calculate the unit cell parameters of individual mineral phases in a mineral assemblage contained in a diamond anvil cell (DAC). Coexisting post-perovskite (ppv) and H-phase were synthesized at 119 GPa and 2500 K from (Mg0.85Fe0.15)SiO3 in a laser-heated DAC. The unit cell parameters of the ppv and coexisting H-phase were determined using multigrain XRD with a 5 μm spatial resolution, close to the size of the X-ray beam, to understand compositional variations across the center area (20-30 μm) in a laser-heated sample. The ppv phase was Fe-depleted and the unit cell volume of ppv decreased by only 0.16 % (corresponding to ~3 % variation of FeSiO3) from the heating center to 10 μm off the center, while the sample pressure remained at 119 GPa in a Ne quasi-hydrostatic environment. The unit cell volume of the H-phase decreased by 0.54 % (~10 % variation of FeSiO3 content) over the same 10 μm distance. Both phases were more Fe-enriched in the slightly hotter center. This observation suggests that thermal diffusion may not be the major driver for the compositional variations of ppv and H-phase in the center portion of a laser-heated sample. Instead, these variations could be caused by a temperature effect on the partitioning between the ppv and H-phase over the small gradient.

  15. A figure of merit for selective absorbers in flat plate solar water heaters

    CSIR Research Space (South Africa)

    Roberts, DE

    2013-12-01

    Full Text Available We derive from first principles an analytical expression for a figure of merit (FM) for a selective solar absorber in a single glazed flat plate water heater. We first show that the efficiency of a collector with an absorber with absorptance α...

  16. Tip-based chemical vapor deposition with a scanning nano-heater

    NARCIS (Netherlands)

    Gaitas, A.

    2013-01-01

    In this preliminary effort, a moving nano-heater directs a chemical vapor deposition reaction (nano-CVD) demonstrating a tip-based nanofabrication (TBN) method. Localized nano-CVD of copper (Cu) and copper oxide (CuO) on a silicon (Si) and silicon oxide (SiO2) substrate from gasses, namely sublimate

  17. 16 CFR Appendix J1 to Part 305 - Pool Heaters-Gas

    Science.gov (United States)

    2010-01-01

    ... Part 305—Pool Heaters—Gas Range Information Manufacturer's rated heating capacity Range of Thermal... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Pool Heaters-Gas J1 Appendix J1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE...

  18. An efficient water flow control approach for water heaters in direct load control

    NARCIS (Netherlands)

    Belov, Alexander; Meratnia, Nirvana; Zwaag, van der Berend Jan; Havinga, Paul

    2014-01-01

    Tank water heaters (WHs) are present in a prevailing number of European households. Serving as energy buffers WHs have come under the spotlight of various direct load control (DLC) programs over the last few decades. Although DLC has proven to be an efficient measure towards daily peak demand shavin

  19. 16 CFR Appendix J2 to Part 305 - Pool Heaters-Oil

    Science.gov (United States)

    2010-01-01

    ... Part 305—Pool Heaters—Oil Range Information Manufacturer's rated heating capacities Range of Thermal... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Pool Heaters-Oil J2 Appendix J2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE...

  20. Development of Multi-Stage Steam Injector for Feedwater Heaters in Simplified Nuclear Power Plant

    Science.gov (United States)

    Narabayashi, Tadashi; Ohmori, Shuichi; Mori, Michitsugu; Asanuma, Yutaka; Iwaki, Chikako

    A steam injector (SI) is a simple, compact and passive pump and also acts as a high-performance direct-contact compact heater to heat up feedwater by using extracted steam from the turbine. To develop high performance compact feedwater heater, it is necessary to quantify the characteristics between physical properties of the flow field. Its performance depends on the phenomena of steam condensation onto the water jet surface and heat transfer in the water jet due to turbulence on to the phase-interface. The analysis was conducted by using CFD code embedded separate two-phase flow models that were confirmed by the experimental data. As the four-stage SI is compact heater, the system is expected to bring about great simplification and materials-saving effects, and high reliability of its operation. Therefore, it is confirmed that the simplification of the power plant by replacing all low-pressure feedwater heaters with the four-stage SI system, having steam extraction pressures equal to those for the existing ABWR system.

  1. Study of Exhaust Emissions Reduction of a Diesel Fuel Operated Heater During Transient Mode of Operation

    Directory of Open Access Journals (Sweden)

    Miklánek Ľubomír

    2014-10-01

    Full Text Available Diesel fuel operated heaters (FOHs are generally used as an independent heat source for any system in which a diesel fuel and battery power is available. Based on the fact that future engines will become even more efficient and thus less waste heat will be available to heat the passenger compartment, independent heat sources will be even more necessary.

  2. 16 CFR Appendix D2 to Part 305 - Water Heaters-Electric

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Electric D2 Appendix D2 to... PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. D2 Appendix D2 to Part 305—Water Heaters—Electric Range Information CAPACITY FIRST HOUR RATING Range of...

  3. 78 FR 7394 - Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters...

    Science.gov (United States)

    2013-02-01

    ... Foreign-Trade Zones Board Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters), Louisville, KY GE Appliances, operator of Subzone 29C, submitted a notification of proposed production activity for its facility in Louisville, Kentucky. The notification conforming to the...

  4. Measure Guideline. Heat Pump Water Heaters in New and Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Owens, Douglas [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs

  5. Local Adaptive Control of Solar Photovoltaics and Electric Water Heaters for Real-time Grid Support

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Mendaza, Iker Diaz de Cerio; Bak-Jensen, Birgitte

    2016-01-01

    , such as electric vehicles, electric water heaters (EWHs) etc. An adaptive control using only local measurements for the EWHs and PVs is proposed in this study to alleviate OV as well as UV issues. The adaptive control is designed such that it monitors the voltage at the point of connection and adjusts active...

  6. Microbunching Instability Effect Studies and Laser Heater Optimization for the SPARX FEL Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Vaccarezza, C.; Chiadroni, E.; Ferrario, M.; Giannessi, L.; Quattromini, M.; Ronsivalle, C.; Venturini, C.; Migliorati, M.; Dattoli, G.

    2010-05-23

    The effects of microbunching instability for the SPARX accelerator have been analyzed by means of numerical simulations. The laser heater counteracting action has been addressed in order to optimize the parameters of the compression system, either hybrid RF plus magnetic chicane or only magnetic, and possibly enhance the FEL performance.

  7. Application for the On-line Isotope Mass Separator ISOLDE Facility: the Target Heater

    CERN Document Server

    Sánchez-Conejo, Jorge

    2003-01-01

    The purpose of the Heater Application is to heat and cool the target and line used on the On-Line Isotope Mass Separator ISOLDE facility up to a desired temperature selected by the user. The application has been developed in Java, making use of the Java Development Kit 1.4 and the PS Java environment.

  8. COMPARISON OF MEASUREMENT TECHNIQUES FOR QUANTIFYING SELECTED ORGANIC EMISSIONS FROM KEROSENE SPACE HEATERS

    Science.gov (United States)

    The report goes results of (1) a comparison the hood and chamber techniques for quantifying pollutant emission rates from unvented combustion appliances, and (2) an assessment of the semivolatile and nonvolatile organic-compound emissions from unvented kerosene space heaters. In ...

  9. Development of the robot for pressurizer electric heater inspection and repairing

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Su, Yong Chil

    1999-01-01

    In this study a robot system has been developed for inspection and maintenance of the pressurizer and the rod heaters. The developed robot system consists of four parts: two links, a support frame, a movable gripper, and a controller box. The robot is attached on the support frame, which is attached at the man-way flange of the pressurizer such that the robot is positioned inside pressurizer. To access arbitrary heater, at first two links horizontally rotate, and then the gripper suspended by two steel wires moves up and down by turing wire drum because the rod heaters are located about 8 meters under the robot and are arranged in two circular rows. The robot must be designed under several constraints such as its weight and collision with pressurized wall or spray nozzle because the robot is positioned and moves inside the pressurizer. To verify that the designed robot is free from collision during installation procedure and it can access any desired rod heater, it is simulated by 3-dimensional graphic software (RobCAD). For evaluating stress of the support frame finite element analysis is performed by using the ANSYS code.

  10. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Water Heaters—Oil Range Information CAPACITY FIRST HOUR RATING Range of Estimated...

  11. Acceptability of the integral solar water heater by householders in the low income urban community

    CSIR Research Space (South Africa)

    Basson, FA

    1984-01-01

    Full Text Available A research and demonstration project on the use and performance of low cost integral solar water heaters in urban low-income dwellings was carried out in 1982/83. The project involved technical and socio-economic components. This report summarises...

  12. 16 CFR Appendix D5 to Part 305 - Water Heaters-Heat Pump

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Heat Pump D5 Appendix D5 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix D5 to Part 305—Water Heaters—Heat Pump Range Information CAPACITY FIRST HOUR RATING Range of...

  13. Guidebook for the Development of a Nationally Appropriate Mitigation Action for Solar Water Heaters

    DEFF Research Database (Denmark)

    Haselip, James Arthur; Lütken, Søren E.; Sharma, Sudhir

    This guidebook provides an introduction to designing government-led interventions to scale up investment in solar water heater (SWH) markets, showing how these interventions can be packaged as Nationally Appropriate Mitigation Actions (NAMAS). Reflecting the changing balance in global greenhouse...

  14. An International Survey of Electric Storage Tank Water Heater Efficiency and Standards

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Alissa; Lutz, James; McNeil, Michael A.; Covary, Theo

    2013-11-13

    Water heating is a main consumer of energy in households, especially in temperate and cold climates. In South Africa, where hot water is typically provided by electric resistance storage tank water heaters (geysers), water heating energy consumption exceeds cooking, refrigeration, and lighting to be the most consumptive single electric appliance in the home. A recent analysis for the Department of Trade and Industry (DTI) performed by the authors estimated that standing losses from electric geysers contributed over 1,000 kWh to the annual electricity bill for South African households that used them. In order to reduce this burden, the South African government is currently pursuing a programme of Energy Efficiency Standards and Labelling (EES&L) for electric appliances, including geysers. In addition, Eskom has a history of promoting heat pump water heaters (HPWH) through incentive programs, which can further reduce energy consumption. This paper provides a survey of international electric storage water heater test procedures and efficiency metrics which can serve as a reference for comparison with proposed geyser standards and ratings in South Africa. Additionally it provides a sample of efficiency technologies employed to improve the efficiency of electric storage water heaters, and outlines programs to promote adoption of improved efficiency. Finally, it surveys current programs used to promote HPWH and considers the potential for this technology to address peak demand more effectively than reduction of standby losses alone

  15. A new regulation for terrace heaters; ERP: parasols chauffants et cuisson mobile

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2003-09-01

    After a year of discussions, the terrace heaters are from now on entirely authorized. They have indeed just coming to be included in a clear and explicit way in the 'safety rule against the fire and panic risks in the establishments receiving the public. Some precise details are given too for the use of LPG in movable kitchens (exhibition). (O.M.)

  16. Structural Benchmark Creep Testing for the Advanced Stirling Convertor Heater Head

    Science.gov (United States)

    Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.; Shah, Ashwin R.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for use on long duration Science missions such as lunar applications, Mars rovers, and deep space missions. For the inherent long life times required, a structurally significant design limit for the heater head component of the ASRG Advanced Stirling Convertor (ASC) is creep deformation induced at low stress levels and high temperatures. Demonstrating proof of adequate margins on creep deformation and rupture for the operating conditions and the MarM-247 material of construction is a challenge that the NASA Glenn Research Center is addressing. The combined analytical and experimental program ensures integrity and high reliability of the heater head for its 17-year design life. The life assessment approach starts with an extensive series of uniaxial creep tests on thin MarM-247 specimens that comprise the same chemistry, microstructure, and heat treatment processing as the heater head itself. This effort addresses a scarcity of openly available creep properties for the material as well as for the virtual absence of understanding of the effect on creep properties due to very thin walls, fine grains, low stress levels, and high-temperature fabrication steps. The approach continues with a considerable analytical effort, both deterministically to evaluate the median creep life using nonlinear finite element analysis, and probabilistically to calculate the heater head s reliability to a higher degree. Finally, the approach includes a substantial structural benchmark creep testing activity to calibrate and validate the analytical work. This last element provides high fidelity testing of prototypical heater head test articles; the testing includes the relevant material issues and the essential multiaxial stress state, and applies prototypical and accelerated temperature profiles for timely results in a

  17. Design, construction, operation and evaluation of a prototype culm combustion boiler/heater unit. Final design of prototype unit

    Energy Technology Data Exchange (ETDEWEB)

    1980-10-01

    A final design of a prototype anthracite culm combustion boiler has been accomplished under Phase I of DOE Contract ET-78-C-01-3269. The prototype boiler has been designed to generate 20,000 pounds per hour of 150 psig saturated steam using low Btu (4000 Btu per pound) anthracite culm as a fuel. This boiler will be located at the industrial park of the Shamokin Area Industrial Corporation (SAIC). This program is directed at demonstrating the commercial viability of anthracite culm fueled FBC steam generation systems.

  18. Studying creation of bulk elementary excitation by heaters in superfluid helium-Ⅱ at low temperatures

    Institute of Scientific and Technical Information of China (English)

    ZAKHARENKO A.A.

    2007-01-01

    In this paper, the obtained experimental results concerning creation of bulk elementary excitations (BEEs) in isotopically pure liquid 4He at low temperatures ~60 mK are discussed. Positive rotons' (R+-rotons) creation by a pulsed heater was studied. Signals were recorded for the following quantum processes: quantum evaporation of 4He-atoms from the free liquid-helium surface by the BEEs of the liquid helium-Ⅱ, and BEEs reflection from the free surface back into the bulk liquid. Typical signals are shown, and ratios of signal amplitudes are evaluated. For long heater pulses from 5 to 10 μs, appearance of the second atomic cloud consisting of evaporated 4He-atoms was observed in addition to the first atomic cloud. It is thought that the first atomic cloud of the evaporated helium atoms consists of very fast 4He-atoms with energies ~35 K evaporated by positive rotons with the special energies ~17 K (~2ER~2×8.6 K with ER representing the roton minimum energy) corresponding to the third non-dispersive Zakharenko wave. The second cloud of slower 4He-atoms was created by surface elementary excitations (SEEs or ripplons) possessing the special energies ~7.15 K representing the binding energy. It was assumed that such SEEs can be created by phonons incoming to the liquid surface with special energies ~6.2 K corresponding to the first non-dispersive Zakharenko wave,which can interact at the liquid surface with the same phonons already reflected from the surface for long heater pulses. Also, some pulsed-heater characteristics were studied in order to better understand the features of such heaters in low temperature experiments.

  19. EFFECT OF DISCRETE HEATER AT THE VERTICAL WALL OF THE CAVITY OVER THE HEAT TRANSFER AND ENTROPY GENERATION USING LBM

    Directory of Open Access Journals (Sweden)

    Mousa Farhadi

    2011-01-01

    Full Text Available In this paper Lattice Boltzmann Method (LBM was employed for investigation the effect of the heater location on flow pattern, heat transfer and entropy generation in a cavity. A 2D thermal lattice Boltzmann model with 9 velocities, D2Q9, is used to solve the thermal flow problem. The simulations were performed for Rayleigh numbers from 103 to 106 at Pr = 0.71. The study was carried out for heater length of 0.4 side wall length which is located at the right side wall. Results are presented in the form of streamlines, temperature contours, Nusselt number and entropy generation curves. Results show that the location of heater has a great effect on the flow pattern and temperature fields in the enclosure and subsequently on entropy generation. The dimensionless entropy generation decreases at high Rayleigh number for all heater positions. The ratio of averaged Nusselt number and dimensionless entropy generation for heater located on vertical and horizontal walls was calculated. Results show that higher heat transfer was observed from the cold walls when the heater located on vertical wall. On the other hand, heat transfer increases from the heater surface when it located on the horizontal wall.

  20. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state